Docket No. 101844.

IN THE

SUPREME COURT

OF

THE STATE OF ILLINOIS

NICOR, INC., et al., Appellants, v. ASSOCIATED ELECTRIC AND

GAS INSURANCE SERVICES LIMITED et al. (Certain

Underwriters at Lloyd’s of London et al., Appellees).

Opinion filed November 30, 2006.

JUSTICE KARMEIER delivered the judgment of the court, with

opinion.

Chief Justice Thomas and Justices Freeman, Fitzgerald, Kilbride,

and Garman concurred in the judgment and opinion.

Justice Burke took no part in the decision.

OPINION

Nicor, Inc., and Northern Illinois Gas Company, doing business

as Nicor Gas Company (hereinafter referred to collectively as Nicor),

are in the business of supplying natural gas to homes and businesses

throughout northern Illinois. The litigation before us today concerns

the obligation of certain of Nicor’s liability insurance carriers to

indemnify the company for sums it expended in connection with the

remediation of mercury contamination caused by the removal of gas

meter regulators from the homes of its residential customers between

1961 and 1978. During the course of the litigation, which spanned a

four-year period between 2000 and 2004, some of the defendant
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insurance carriers settled. The defendants designated by the parties as

“certain underwriters at Lloyd’s of London and certain London

market insurance companies” (the London Insurers) did not. In late

2004, the circuit court entered judgment in favor of Nicor and against

the London Insurers in the amount of $10,281,703.46. The London

Insurers appealed. The appellate court reversed and remanded for

further proceedings on the sole ground that the circuit court had

misapplied the terms of the applicable insurance policies. 362 Ill. App.

3d 745. We granted Nicor’s petition for leave to appeal. 177 Ill. 2d R.

315. For the reasons that follow, we now affirm the appellate court’s

judgment.

BACKGROUND

Nicor installs meters at the homes of its residential customers to

measure the amount of natural gas the customers consume. Each

meter contains a regulator which controls the flow of natural gas into

the residence. The regulators decrease the high pressure used to

transport natural gas through the delivery system to the lower

pressures utilized within customers’ homes. As a safety feature, the

regulators include a relief valve that opens if the pressure of the gas

being supplied to a customer’s home is excessive.

Until 1961, Nicor utilized gas meters whose regulators included

relief valves containing the metallic element mercury. The quantity of

mercury in a given unit ranged from 11⁄2 to 4 ounces. The mercury,

which remained liquid at room temperature, served as a “cap” on the

relief valve. If the gas pressure in the system was too high, it would

force the mercury “cap” aside, enabling the gas to pass through a vent

and escape safely to the outside of the home.

Beginning in 1961, Nicor initiated a systemwide program to

remove regulators containing mercury from inside their customers’

homes and to replace them with new regulators utilizing a springactivated relief mechanism. The new regulators with spring-activated

relief valves were part of temperature-compensating meter sets that

could be installed on the outside of customers’ homes. No mercury

was used in any part of these replacement meter sets.

In implementing its replacement program during this period,

Nicor did not dispatch crews specifically to exchange meters. New
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meters were installed only if an old-style meter was discovered by a

Nicor service crew sent to the area for some other reason, such as to

perform maintenance or repair work at a customer’s home or to

upgrade a neighborhood’s natural gas service. Whenever a Nicor crew

found that a customer’s meter set was located in the house, it would

remove that meter set and install one of the new temperaturecompensating meters outside the residence. As part of this process,

the Nicor crew would replace the old regulator containing a mercury

relief valve with one of the new regulators equipped with a springactivated relief valve.

The replacement process was normally safe and unremarkable. In

a very small number of cases, however, regulators were tilted or

tipped in a way that allowed mercury to spill out and contaminate the

customer’s home. The problem of contamination surfaced during the

summer of 2000, when Nicor learned that a contractor it had hired

had spilled mercury in a customer’s home while removing one of the

old regulators.

The initial contamination report was followed by revelations that

additional mercury spills had occurred in the homes of other Nicor

customers. Class actions seeking damages for personal injury and

property damage were soon instituted against the company on behalf

of all those who had been affected by the mercury spills resulting from

the replacement of the old-style regulators. The Illinois Attorney

General, joined by the State’s Attorneys of Cook, Du Page and Will

Counties, also brought a separate suit against Nicor in the circuit

court of Cook County. The Attorney General’s action demanded,

inter alia, that Nicor be required to investigate the extent of mercury

contamination caused by replacement of its natural gas regulators, to

clean up the contamination, and to assist all potentially affected

individuals in determining whether they had suffered any mercury

exposure.

Nicor was able to reach a settlement with the Attorney General’s

office shortly after it filed its action. The class actions were

consolidated and settled as well. Under the terms of the settlement in

the Attorney General’s action, Nicor was required to identify all

homes within its service area that may have been contaminated by

mercury from an old-style regulator and to undertake appropriate

measures to clean up any contamination that was detected. Nicor
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subsequently ascertained that over 300,000 of its customers’ homes

may have had regulators with relief valves containing mercury.

Approximately one third of those homes were determined to have

been constructed after the period when the old-style relief valves were

no longer being installed in new construction and were therefore not

at risk for mercury contamination. The remaining 200,000 homes were

physically inspected. Of those, 1,070, or approximately one-half of

1%, were found to contain impermissibly high levels of mercury. For

the purposes of this litigation, the parties have stipulated that the

mercury found in those 1,070 homes “was more likely than not due to

the removal of mercury-containing regulators from inside the homes.”

The process of investigating, identifying and remediating the

mercury contamination in its customers’ homes cost Nicor

approximately $90 million. Nicor turned to its insurers to obtain

indemnification for those expenses. When the insurers refused to pay

Nicor’s claims, the company brought this action against them in the

circuit court of Cook County. Nicor’s suit sought declaratory relief

and damages based on breach of contract and anticipatory breach of

contract.

All of the defendant insurance carriers that were still solvent

agreed to a settlement with Nicor, with the exception of the London

Insurers. Nicor had purchased polices from the London Insurers

between 1961 and 1978. The policies issued by the London Insurers

were excess/umbrella general liability policies under which the insurers

were required to indemnify Nicor for all sums Nicor became legally

obligated to pay because of property damage caused by or growing

out of “an occurrence.” Under the policies issued between 1961 and

November 1976, an “occurrence” was defined as “one happening or

series of happenings arising out of or due to one event taking place

during the term of this contract.” The policies issued from November

1976 through 1978 defined an “occurrence” as:

“(1) an accident, or (2) event or continuous or repeated

exposure to conditions which result in bodily injury, personal

injury, death or physical damage to or destruction of tangible

property, including the loss of use. All damages arising out of

such exposure to substantially the same general conditions

shall be considered as arising out of one occurrence.”
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Under all of the London Insurers’ policies, the insurers’

obligation to provide indemnification was subject to a self-insured

retention (SIR), that is, a deductible. The amount of the deductible

varied, but was never less than $100,000 per occurrence. Nicor

therefore could not obtain indemnification from the London Insurers

unless and until its loss for a covered occurrence was more than

$100,000. Once the SIR amount had been satisfied, the London

Insurers were obligated to indemnify only for the amount in excess of

the SIR up to a contractually specified limit of liability. The liability

limitations ranged from $750,000 to more than $4 million depending

on the policy.

Of the 1,070 homes where mercury contamination was

discovered and remediation was carried out, 195 were subject to the

policies issued to Nicor by the London Insurers between 1961 and

1978. For the purposes of this litigation, there is no dispute that the

investigation and remediation costs attributable to each of those 195

homes, individually, was less than the applicable SIR amount. How

the term “occurrence” was construed under the governing policies

therefore had major consequences for calculating the extent of the

London Insurers’ duty to provide indemnification. If each of the 195

spills constituted a separate occurrence within the meaning of the

policies, the London Insurers would owe nothing. If, on the other

hand, the spills were conceived as constituting but a single occurrence,

the amount the London Insurers would be required to pay Nicor

would be substantial.

In order to resolve the occurrence issue, Nicor and the London

Insurers filed cross-motions for summary judgment pursuant to

section 2–1005 of the Code of Civil Procedure (735 ILCS 5/2–1005

(West 2004)). Nicor, for its part, asserted that its liability for the

mercury contamination at the 195 homes arose from one occurrence,

obligating it to pay a single SIR per policy year to cover all of the

contamination claims. The London Insurers, by contrast, contended

that Nicor’s liability arose from 195 separate occurrences and that

Nicor’s claims were therefore subject to 195 separate SIRs.

The circuit court denied the London Insurers’ motion, but

granted summary judgment in favor of Nicor. In the circuit court’s

view, the contamination was attributable to Nicor’s consistent and

routine “failure to invoke proper procedures to safely remove the
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mercury regulators.” The court held that this “systematic failure to

consistently remove the mercury regulators resulted in a single

‘occurrence’ under the [London Insurers’] policies.”

Following the circuit court’s ruling, Nicor and the London

Insurers stipulated to the remaining issues in the case, including: (1)

that mercury spills took place in every policy period between 1961

and 1978, (2) that the SIRs under the policies in effect during those

years totaled $950,000, and (3) that the London Insurers’ pro rata

liability for the $90 million in losses ultimately incurred by Nicor after

satisfaction of the $950,000 in SIRs totaled $10,281,703.46. Based

upon these stipulated facts, the circuit court entered final judgment in

favor of Nicor and against the London Insurers in the amount of

$10,281,703.46.

As noted at the outset of this opinion, the appellate court

reversed and remanded for further proceedings. 362 Ill. App. 3d 745.

The sole ground for its decision was that the circuit court had

misapplied the definition of occurrence contained in the applicable

insurance policies. In the appellate court’s view, the damages were not

caused by Nicor’s systemwide failure to remove the regulators safely.

Rather, they were the product of separate and independent acts,

occurring “in an isolated number of cases as a result of [individual

servicemen’s] actions or the particular circumstances in each

residence.” 362 Ill. App. 3d at 754.

Nicor petitioned our court for leave to appeal. 177 Ill. 2d R. 315.

We granted its petition. We subsequently allowed BorgWarner, Inc.,

to file an amicus curiae brief in support of Nicor. See 155 Ill. 2d R.

345. We also allowed John Crane, Inc., to file an amicus curiae brief

in favor of the London Insurers.

ANALYSIS

The sole issue raised by Nicor in this appeal is whether the circuit

correctly held that the mercury contamination in the 195 homes for

which it submitted claims under the policies it purchased from the

London Insurers between 1961 and 1978 constituted a single

occurrence within the meaning of those policies. The construction of

the provisions of an insurance policy is a question of law, subject to
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de novo review. Illinois Farmers Insurance Co. v. Marchwiany, No.

101598, slip op. at 3 (September 21, 2006).

Insurance policies are subject to the same rules of construction

applicable to other types of contracts. See Continental Casualty Co.

v. McDowell & Colantoni, Ltd., 282 Ill. App. 3d 236, 241 (1996). A

court’s primary objective is to ascertain and give effect to the

intention of the parties as expressed in the agreement. Crum & Forster

Managers Corp. v. Resolution Trust Corp., 156 Ill. 2d 384, 391

(1993). In performing that task, the court must construe the policy as

a whole, taking into account the type of insurance purchased, the

nature of the risks involved, and the overall purpose of the contract.

Travelers Insurance Co. v. Eljer Manufacturing, Inc., 197 Ill. 2d 278,

292 (2001), quoting American States Insurance Co. v. Koloms, 177

Ill. 2d 473, 479 (1997).

The words of a policy should be accorded their plain and ordinary

meaning. State Farm Mutual Automobile Insurance Co. v. Villicana,

181 Ill. 2d 436, 441 (1998). Where the provisions of a policy are clear

and unambiguous, they will be applied as written (United States Fire

Insurance Co. v. Schnackenberg, 88 Ill. 2d 1, 4 (1981)) unless doing

so would violate public policy (State Farm Mutual Automobile

Insurance Co. v. Villicana, 181 Ill. 2d at 442). That a term is not

defined by the policy does not render it ambiguous, nor is a policy

term considered ambiguous merely because the parties can suggest

creative possibilities for its meaning. Rather, ambiguity exists only if

the term is susceptible to more than one reasonable interpretation.

Lapham-Hickey Steel Corp. v. Protection Mutual Insurance Co., 166

Ill. 2d 520, 530 (1995).

Because insurance contracts are issued under given

circumstances, they are not to be interpreted in a factual vacuum. A

policy term that appears unambiguous at first blush might not be such

when viewed in the context of the particular factual setting in which

the policy was issued. Glidden v. Farmers Automobile Insurance

Ass’n, 57 Ill. 2d 330, 336 (1974). Governing legal authority must, of

course, be taken into account as well, for a policy term may be

considered unambiguous where it has acquired an established legal

meaning. United States Fire Insurance Co. v. Schnackenberg, 88 Ill.

2d at 5. Where ambiguity does exist, the policy will be construed

strictly against the insurer, who drafted the policy (Travelers
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Insurance Co. v. Eljer Manufacturing, Inc., 197 Ill. 2d at 293), and

liberally in favor coverage for the insured (see Hobbs v. Hartford

Insurance Co. of the Midwest, 214 Ill. 2d 11, 17 (2005)).

As we have just discussed, the case before us today concerns

construction of the provisions in Nicor’s insurance policies dealing

with occurrences. The question is not, however, whether a covered

occurrence took place. The London Insurers do not dispute that

events transpired which would qualify as an occurrence within the

meaning of both versions of the liability policies issued to Nicor by the

London Insurers between 1961 and 1978. The issue presented by this

litigation is more complex. The problem with which the lower courts

wrestled and which we must now resolve is how many occurrences

there were, 1 or 195.

The definitions of occurrence used in the insurance policies issued

by the London Insurers are typical of commercial liability policies. As

in our case, such policies often describe an occurrence using terms

such as “accident,” “happening” or “event.” While the form of such

terms is singular, what seems like a single accident, happening, or

event to the person who triggered the incident giving rise to the loss

for which coverage is sought may be perceived as multiple accidents,

happenings or events from the perspective of those who sustained

injury or damage as a result of the insured’s conduct. Accordingly, the

terms of the insurance policy are not always sufficient, standing alone,

to permit a definitive determination as to whether a particular case

involves one occurrence or many.

In order to overcome this problem, American courts have

developed two basic approaches for assessing the number of

occurrences that took place within the meaning of policies such as

those at issue in this case, the cause theory and the effect theory. The

effect theory, as its name implies, determines the number of accidents

or occurrences by looking at the effect an event had, i.e., how many

individual claims or injuries resulted from it. Under the cause theory,

on the other hand, the number of occurrences is determined by

referring to the cause or causes of the damages. See Illinois National

Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d 1091, 1094-95

(1989).

The difference between these two approaches is illustrated by the

following hypothetical. Assume that a motorist is traveling down a
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street lined with parked cars. Looking away from the roadway to

change the station on his car’s radio, the motorist allows his vehicle

to wander. As a result, his car strikes the sides of three of the parked

cars in succession, damaging each of them. The owners of the three

damaged vehicles sue, and the vehicle owner seeks indemnification

from his automobile insurance carrier. Under the effect theory, the fact

that three cars were damaged and three claims were filed would mean

that there were three “occurrences” for purposes of determining

liability coverage, absent specific policy language to the contrary.

Under the cause theory, on the other hand, the fact that the damage

to all three vehicles resulted from the same conditions and was

inflicted as part of an unbroken and uninterrupted continuum would

yield the conclusion that there was only one occurrence. See Illinois

National Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d at 1095-96

(discussing application of cause theory to traffic accidents).

Neither the cause theory nor the effect theory inevitably favors

one party to an insurance contract over another. Whether a particular

approach would be more beneficial to the insurance carrier or its

insured depends on the limits of coverage, the number of claims, the

magnitude of the claimant’s losses, and the size of applicable

deductibles in a given case. For example, attributing damages

sustained by multiple claimants to multiple occurrences would be

beneficial to the insured where the claims are large relative to the peroccurrence policy limits, for it would maximize the coverage the

insured will receive. It would benefit the insurance carrier where, as

in this case, the individual claims are each smaller than the applicable

deductible, for it would allow the insurer to avoid paying anything.

The full loss would be borne by the insured.

A majority of jurisdictions have adopted the cause theory to

determine the number of occurrences under general liability insurance

policies of the type at issue in this case. Although this court has not

addressed the issue, our appellate court has consistently concluded

that the cause theory represents the approach which the courts of

Illinois should follow. See Aetna Casualty & Surety Co. v. O’Rourke

Bros., Inc., 333 Ill. App. 3d 871, 881-82 (2002); Illinois Central R.R.

Co. v. Accident & Casualty Co. of Winterthur, 317 Ill. App. 3d 737,

745-46 (2000); United States Gypsum Co. v. Admiral Insurance Co.,

268 Ill. App. 3d 598, 648 (1994); Illinois National Insurance Co. v.
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Szczepkowicz, 185 Ill. App. 3d at 1094-95; Mason v. Home Insurance

Co. of Illinois, 177 Ill. App. 3d 454, 459-60 (1988). In accordance

with this line of authority, the appellate court’s decision in the case

before us adhered to the cause theory in construing and applying the

subject policies. Neither Nicor nor the London Insurers question that

aspect of the appellate court’s decision, and we agree that the cause

theory represents the law of Illinois.

To properly understand the cause theory as interpreted and

applied in Illinois, one must consider the principal appellate court

cases in which the doctrine has been employed. The first opinion to

adopt the cause theory was Mason v. Home Insurance Co. of Illinois,

177 Ill. App. 3d 454 (1988). Mason was a declaratory judgment

action to determine the amount of liability coverage available to the

owner of a restaurant with respect to claims brought by restaurant

diners who were stricken with botulism poisoning after consuming

patty melt sandwiches containing tainted onions. The tainted food was

served to numerous customers over a three-day period. Applying the

cause theory, the appellate court held that the restaurant did not

become liable until it actually served a portion of the tainted food and

that each time a customer was served constituted a separate and

distinct occurrence within the meaning of the policy. Mason v. Home

Insurance Co. of Illinois, 177 Ill. App. 3d at 461. In reaching this

conclusion, the court distinguished situations where there was an

uninterrupted and continuing cause from which all of the injuries

resulted, such as where guests’ property is damaged in a hotel fire or

when an open faucet on an upper floor of a building causes water

damage to property on lower floors. Mason v. Home Insurance Co.

of Illinois, 177 Ill. App. 3d at 461.

Mason derived its analysis from a federal court opinion,

Michigan Chemical Corp. v. American Home Assurance Co., 728

F.2d 374 (6th Cir. 1984), a declaratory judgment action to determine

how much insurance coverage was available to pay farmers who had

sustained property damage when their livestock consumed tainted

feed. The contamination occurred when Michigan Chemical

Corporation (MCC). accidently filled an order for a livestock feed

supplement with flame retardant, the feed vendor failed to realize the

mistake, and the flame retardant was mixed with regular feed and sold

to farmers. As a result of the mistake, tens of thousands of farm
 1

For purposes of construing the relevant insurance policy provisions, the

appellate court considered “accident” to be synonymous with “occurrence.”

Illinois National Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d at 1094.

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animals had to be destroyed, and hundreds of claims were

subsequently filed against MCC and the feed vendor.

MCC and a reinsurance company involved in the case argued that

each of the claims constituted a separate occurrence within the

meaning of the applicable insurance policies. The federal court

rejected that argument. Following the view it believed the courts of

Illinois would adopt if presented with the question, it held that the

number of occurrences was determined not on the basis of the number

of injuries, but on the cause or causes of the injuries. In its opinion,

the cause of the injury from which MCC’s liability arose was the

misshipment of the flame retardant and that each separate

misshipment, if more than one took place, would constitute a separate

occurrence. Michigan Chemical Corp. v. American Home Assurance

Co., 728 F.2d at 383.

The foregoing decisions were followed by Illinois National

Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d 1091 (1989). In that

case, an insurance company brought a declaratory judgment action to

ascertain the amount it was obligated to pay under a liability insurance

policy for two lawsuits filed against its insureds. Those lawsuits arose

from collisions involving a tractor-trailer unit driven by the defendant

and two automobiles. At the time of the collisions, the left rear side

clearance light of the tractor-trailer unit was inoperable and there was

fog in the area.

The first collision took place when the defendant blocked traffic

while preparing to turn and a motorist struck the rear wheels of his

rig. After this initial accident, the defendant moved the rig forward

and stopped again. In so doing, he failed to completely remove the

tractor-trailer unit from all lanes of traffic. Approximately five minutes

later, another automobile smashed into the rig, just forward of the

point of impact in the first crash. The question in the case was whether

these events constituted one accident or occurrence or two within the

meaning of the defendant’s liability insurance policy, under which

coverage was limited to $300,000 per accident.1
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Looking to the language of the policy and the facts of the case,

the appellate court concluded that under the cause theory, the two

collisions could not be said to have resulted from the same negligent

act. Distinguishing situations where one car ricochets off another and

then strikes a third vehicle, the court held that there was no single

force and no unbroken or uninterrupted continuum that, once set in

motion, caused multiple injuries. The court further noted that the

conditions resulting in each collision had changed. After the first

accident, the defendant should have realized the risk posed in allowing

his rig to obstruct traffic lanes while it was foggy. He had the

opportunity to take corrective measures by moving the rig off the

road, but failed to do so. Instead, by remaining on the roadway and

moving forward, which opened a path for traffic that had been

blocked at the time of the first collision, he created a new and different

hazard to navigation for cars following from behind. The court

therefore concluded that there was a separate and second cause for

the subsequent collision and that there were two accidents or

occurrences under the relevant insurance policy. Illinois National

Insurance Co. v. Szczepkowicz, 185 Ill. App. 3d at 1096.

Two years afer Illinois National Insurance Co. v. Szczepkowicz,

185 Ill. App. 3d 1091 (1989), the appellate court decided Village of

Camp Point v. Continental Casualty Co., 219 Ill. App. 3d 86 (1991).

Camp Point was a declaratory judgment action brought by a village

against its attorney and his insurance company to determine how much

coverage was available for the attorney’s alleged malpractice under a

series of professional liability policies which the insurance company

had issued. The basis for the underlying malpractice claim was that the

attorney had advised the village that it could pledge revenue-sharing

and sales tax funds in connection with multiple bond transactions

when he knew that such pledges were not approved by statute. The

trial court construed the case as involving one unified transaction,

namely, the attorney’s misinterpretation of the governing law when

advising the village pursuant to a contract of employment which was

to be performed over an extended period of time, and that there was

therefore only one occurrence within the meaning of the attorney’s

professional liability policies. Village of Camp Point v. Continental

Casualty Co., 219 Ill. App. 3d at 97. The appellate court, however,

rejected that interpretation. It held that each individual instance in
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which the attorney rendered erroneous legal advice was a separate

cause of the village’s injuries and that there were therefore multiple

occurrences for insurance coverage purposes. Village of Camp Point

v. Continental Casualty Co., 219 Ill. App. 3d at 103.

The same approach was taken in Roman Catholic Diocese of

Joliet, Inc. v. Lee, 292 Ill. App. 3d 447 (1997), a declaratory

judgment action to determine, inter alia, whether multiple acts of

sexual molestation committed by a priest against a female minor

constituted a single occurrence within the meaning of the insurance

policies held by the Diocese in which the priest served. The appellate

court held that it did not. Relying on Mason v. Home Insurance Co.

of Illinois, 177 Ill. App. 3d 454 (1988), and decisions from other

jurisdictions, and based on the facts of the case and the language of

the applicable policies, the court held that it was the repeated

exposure of the minor to the negligently supervised priest that

provided the basis for indemnification and that, “[a]ccordingly, the

minor’s exposure to the negligently supervised priest in each of the

policy periods constituted a separate occurrence.” Roman Catholic

Diocese of Joliet, Inc. v. Lee, 292 Ill. App. 3d at 455.

To the same effect is Illinois Central R.R. Co. v. Accident &

Casualty Co. of Winterthur, 317 Ill. App. 3d 737 (2000), an action

between a railroad and its insurance carriers to determine the extent

of the carriers’ obligation to indemnify the railroad for over $13

million in defense and settlement costs it incurred as the result of

discriminatory hiring decisions made by one of its employees. In that

case, the railroad argued that only a single occurrence was involved,

namely, its decision to delegate hiring decisions to the employee who

made the decisions which subjected it to liability. The appellate court

rejected that contention. Under its view of the cause theory, the

discriminatory hiring decisions did not comprise the continuation of

a single process or condition, but rather were the product of multiple

individual acts which took place over an extended period of time. The

court therefore concluded that each of the discriminatory hiring

decisions was a separate occurrence within the meaning of the

governing policy provisions. Illinois Central R.R. Co. v. Accident &

Casualty Co. of Winterthur, 317 Ill. App. 3d at 746-50.

In all of the foregoing cases, the insurance policies’ definition of

occurrence was similar to the definitions contained in the policies
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involved in this case. The policy in Mason defined an occurrence as

either an accident or happening or event or a continuous or repeated

exposure to conditions which unexpectedly and unintentionally causes

injury. It further stated that all damages arising out of such exposure

to substantially the same conditions shall be considered as arising out

of one occurrence. Mason, 177 Ill. App. 3d at 459.

In Michigan Chemical Corp. v. American Home Assurance Co.,

one set of policies defined occurrence as “an accident or a happening

or event or a continuous or repeated exposure to conditions which

unexpectedly and unintentionally results in personal injury, property

damage or advertising liability during the policy period” and stated

that “[a]ll such exposure to substantially the same general conditions

existing at or emanating from one premises location shall be deemed

one occurrence.” Michigan Chemical Corp. v. American Home

Assurance Co., 728 F.2d at 378. Another set of policies similarly

provided that with respect to property damage, an occurrence was “1)

an accident or 2) continuous or repeated exposure to conditions which

results in injury to or destruction of tangible property, including

consequential loss resulting therefrom, while this agreement is in

effect” and that “[a]ll damages arising out of such exposure to

substantially the same general conditions shall be considered as arising

out of one occurrence.” (Emphases omitted.) Michigan Chemical

Corp. v. American Home Assurance Co., 728 F.2d at 378.

The policies in Roman Catholic Diocese of Joliet, 292 Ill. App.

3d at 449-50 likewise stated that an occurrence was “an accident or

happening or event or a continuous or repeated exposure to

conditions which unexpectedly and unintentionally results [sic] in

personal injury, or damage to property during the policy period.” The

policies also provided that all exposure to substantially the same

general conditions existing at or emanating from one location was to

be deemed one occurrence.

Under the policy considered in Illinois Central R.R. Co., 317 Ill.

App. 3d at 745, the term occurrence meant “one or more accidents or

disasters and/or series of accidents or disasters arising out of or

resulting from one event.” In Illinois National Insurance Co. v.

Szczepkowicz, 185 Ill. App. 3d at 1094, “one accident” (which was

viewed as synonymous with occurrence) was defined as “all bodily

injury and property damage resulting from continuous or repeated
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exposure to substantially the same conditions.” Camp Point’s policy

stated simply that with regard to professional services, an occurrence

was “an error, negligent omission or negligent act or a series of

related errors, negligent omissions or negligent acts, regardless of the

number of claims or claimants.” Village of Camp Point, 219 Ill. App.

3d at 88. In none of these six cases was the term occurrence found to

be ambiguous.

As our discussion has indicated, all of the foregoing cases

ultimately concluded that covered damages resulted from multiple

occurrences. There have been a few decisions, however, in which the

damages were found to be the product of a single occurrence. The

first Illinois appellate court case to have so found is United States

Gypsum Co. v. Admiral Insurance Co., 268 Ill. App. 3d 598 (1994),

a declaratory judgment action brought by United States Gypsum

Company (Gypsum) against its insurers to obtain coverage for actions

filed against it based on its manufacture and sale of building material

containing asbestos. The building material consisted primarily of

ceiling finishing plaster which was installed at various locations at

various times between 1937 and the 1970s. United States Gypsum Co.

v. Admiral Insurance Co., 268 Ill. App. 3d at 607-08.

Among the issues raised in the case was whether the actions

giving rise to Gypsum’s liability constituted multiple occurrences for

purposes of calculating the deductible limits under certain of

Gypsum’s liability policies. Those policies contained language similar

to that used in the cases we have already discussed. One set of policies

provided that “[t]he deductible amount shall apply ‘per occurrence’ to

the Bodily Injury and Property Damage combined regardless of the

number of persons or organizations seeking damages” and that “[a]ll

damages arising out of a common defect, condition or cause shall be

considered as arising out of one occurrence.” United States Gypsum

Co. v. Admiral Insurance Co., 268 Ill. App. 3d at 648. A second set

of policies stated that “ ‘occurrence’ shall mean sudden or continuous

or repeated exposure to any condition resulting in *** injury or

destruction during the policy period” and that “all such injury or

destruction caused by continuous or repeated exposure to

substantially the same condition shall be deemed to result from one

occurrence.” United States Gypsum Co. v. Admiral Insurance Co.,

268 Ill. App. 3d at 647.
-16-

Looking first to this policy language, taking into account the

cause theory for determining the number of occurrences under a

liability policy, and considering the factual circumstances giving rise

to Gypsum’s liability, the appellate court concluded that the operative

cause was “the continuing process of the manufacture and sale of

asbestos-containing products.” United States Gypsum Co. v. Admiral

Insurance Co., 268 Ill. App. 3d at 649. Central to the court’s analysis

was the nature of the product involved. “Generally,” the court

observed, it has been held that “ ‘if the continuous production and sale

of an intrinsically harmful product results in similar kinds of injury or

property damage, then all such injury or property damage results from

a common occurrence.’ [Citations.]” United States Gypsum Co. v.

Admiral Insurance Co., 268 Ill. App. 3d at 650. The court further

took into account the nature of Gypsum’s involvement in the process

that gave rise to the damages for which indemnification was sought.

Citing Mason v. Home Insurance, 177 Ill. App. 3d at 459-60, for the

proposition that the type of activity in which the insured engages

should be considered in determining the number of occurrences, the

court rejected the argument that each installation of asbestoscontaining building material should be viewed as a separate

occurrence. In the court’s view:

“[i]t would be unwise and without support in case law to

determine that each installation of the asbestos-containing

products constituted a separate occurrence when Gypsum’s

liability is predicated on its involvement in the manufacture

and sale of the products rather than the installation of the

products.” United States Gypsum Co. v. Admiral Insurance

Co., 268 Ill. App. 3d at 651.

The analysis employed in United States Gypsum Co. v. Admiral

Insurance Co., 268 Ill. App. 3d 598, is consistent with that followed

by the United States District Court for the Northern District of Illinois

in Household Manufacturing, Inc. v. Liberty Mutual Insurance Co.,

1987 U.S. Dist. LEXIS 1008 (N.D. Ill. February 11, 1987), mod. on

other grounds, 1987 U.S. Dist. LEXIS 10837 (N.D. Ill. November

16, 1987). Household Manufacturing, Inc. involved a dispute over an

insurance company’s alleged failure to indemnify a company for

damages arising from the company’s manufacture and sale of a plastic

hot-cold pressure plumbing system (the Quest system) for residential
-17-

use. The Quest system was manufactured and then supplied to

plumbing contractors throughout the United States on a continuous

basis over multiple years. Numerous lawsuits ensued, claiming that the

system was defective and had caused property damage. Those

lawsuits were brought primarily on theories of strict liability, tort,

breach of warranty and negligence. Household Manufacturing, 1987

U.S. Dist. LEXIS 1008, *1.

The principal issue in the case was whether the claims for which

coverage was sought constituted one occurrence or multiple

occurrences within the meaning of the applicable liability policies. The

company which manufactured and sold the system argued that there

was only a single occurrence, that it was therefore subject to only one

“stop loss” amount, and that all sums included within ratable incurred

losses above that single stop loss amount must be indemnified by its

insurer up to the policy limits.

The policies in question defined occurrence as “an accident,

including continuous or repeated exposure to conditions, which results

in ‘bodily injury’ or ‘property damage’ neither expected nor intended

from the standpoint of the ‘insured.’ ” Household Manufacturing,

1987 U.S. Dist. LEXIS 1008, *5-6. The polices further provided that

for purposes of determining liability, “all ‘personal injury’ and all

‘property damage’ arising out of continuous or repeated exposure to

substantially the same general conditions *** shall be considered as

arising out of one occurrence.” Household Manufacturing, 1987 U.S.

Dist. LEXIS 1008, *6.

In applying these provisions to the particular facts of the case in

accordance with the cause theory, the court agreed with the

manufacturer’s position. The court observed that it had to rely on

“ ‘the ordinary meaning of the words [in the policy], in relation to the

business risk to be insured against,’ ” namely, “ ‘protection from

liability from a defective product produced in a continuous flow of

production and intended for widespread use *** ending in a multitude

of consumer products in many hands.’ [Citation.]” Household

Manufacturing, 1987 U.S. Dist. LEXIS 1008, *12. According to the

court, the manufacturer in this case sold its system on a mass basis,

“and it was anticipated that any defects in the system would affect a

large number of persons in the chain of distribution.” Household

Manufacturing, 1987 U.S. Dist. LEXIS 1008, *12. The continuous
 2

Single occurrences were also involved in two additional appellate court

cases, Outboard Marine Corp. v. Liberty Mutual Insurance Co., 283 Ill.

App. 3d 630 (1996) , which pertained to the ongoing pollution of Waukegan

-18-

and repeated manufacture and sale of an allegedly defective product

on a mass basis is what gave rise to the manufacturer’s liability and to

its right to recover under the policies and therefore constituted the

single, unitary cause of the claims against the manufacturer.

Accordingly, the court concluded, there was but one occurrence

within the meaning of the insurance policies, and the insurer was

obligated to indemnify the manufacturer for all ratable incurred losses

over the stop loss amount. Numerous cases from other jurisdictions

involving the sale of defective products by an insured manufacturer

were cited by the court in support of this holding. See Household

Manufacturing, 1987 U.S. Dist. LEXIS 1008, *14-20.

A single cause was also found in Aetna Casualty & Surety Co. v.

O’Rourke Bros., Inc., 333 Ill. App. 3d 871 (2002), a declaratory

judgment action to settle insurance coverage questions arising from

claims filed against the insured, a consumer electronics distributor,

based on its scheme to defraud costumers in connection with the sale

and financing of satellite systems. Under the applicable liability policy,

the insurer’s obligation to indemnify the distributor for covered

damages was subject to a $10,000 retained limit. The retained limit,

which operated like a deductible, applied to “any one occurrence or

offense.” An occurrence, in turn, was defined as “an accident,

including continuous or repeated exposure to substantially the same

general harmful conditions.” Aetna Casualty & Surety Co. v.

O’Rourke Bros., Inc., 333 Ill. App. 3d at 881. Applying the analysis

set forth in United States Gypsum Co. v. Admiral Insurance Co., 268

Ill. App. 3d 598, the court held that the cause of the claims for which

indemnification was sought was the distributor’s fraudulent sales

campaign. In the court’s view, that campaign was not a series of

separate and discrete events, but rather a single, continuing process.

The court therefore concluded that there was only one occurrence for

purposes of the liability policy. Accordingly, the retained limit amount

did not apply to each individual claim. Instead, it was to be applied

only once to all of the claims combined. Aetna Casualty & Surety Co.

v. O’Rourke Bros., Inc., 333 Ill. App. 3d at 882.2
Harbor caused by the insured’s manufacturing plant, and Missouri Pacific

R.R. Co. v. International Insurance Co., 288 Ill. App. 3d 69 (1997),

involving claims by the insured’s employees for on-the-job hearing loss and

asbestos exposure. In neither of those cases, however, was the issue of single

or multiple occurrences raised in the same context that it is presented here.

The principal issue they addressed is how coverage should be allocated

among different policies covering different periods of time. See also Hartford

Casualty Insurance Co. v. Medical Protective Co. of Fort Wayne, Indiana,

266 Ill. App. 3d 781 (1994) (doctor’s negligence which took place during

multiple policy periods constituted single occurrence and policies covering

the separate periods could not be stacked).

-19-

Applying the foregoing body of case law, the appellate court in

the case before us today concluded that where each asserted loss is the

result of a separate and intervening human act, whether negligent or

intentional, or each act increased the insured’s exposure to liability,

Illinois law will deem each such loss to have arisen from a separate

occurrence within the meaning of liability policies containing language

similar to that used in the policies issued to Nicor by the London

Insurers. 362 Ill. App. 3d at 753. By contrast, where the damages for

which coverage is sought resulted from the manufacture and sale of

defective products or a fraudulent sales scheme, the loss will be found

to have emanated from a single cause and there will be but one

occurrence for purposes of the applicable policies. 362 Ill. App. 3d

752.

The parties to this case have not asserted that the losses incurred

by Nicor were the result of the manufacture and sale of defective

products or a fraudulent sales scheme. The appellate court therefore

concluded that cases such as Household Manufacturing, Inc. v.

Liberty Mutual Insurance Co., 1987 U.S. Dist. LEXIS 1008 (N.D. Ill.

February 11, 1987); United States Gypsum Co. v. Admiral Insurance

Co., 268 Ill. App. 3d 598 (1994), and Aetna Casualty & Surety Co.

v. O’Rourke Bros., Inc., 333 Ill. App. 3d 871 (2002), were

distinguishable. In the appellate court’s view, this dispute fell instead

under the line of cases beginning with Mason v. Home Insurance Co.

of Illinois, 177 Ill. App. 3d 454 (1988), where each asserted loss was

the result of a separate and intervening human act or each act
 3

Nicor contends that the true incidence of mercury contamination is

actually unknown because early spills may have evaporated and left no

traces by the time testing was undertaken. Aside from being entirely

speculative, this observation is irrelevant. The purpose of this litigation is to

resolve responsibility for costs incurred in detecting and remediating mercury

contamination that was still present in customers’ homes. If a spill had

evaporated and left no traces, there could be no dispute regarding who should

bear the burden of remediation costs, for no remediation was necessary. 

-20-

increased the insured’s exposure to liability. Based on that line of

cases, applied in the factual context of this case and in light of the

language used in the pertinent policies, the appellate court held that

each of the 195 mercury spills subject to the London Insurers’ policies

constituted a separate occurrence. 362 Ill. App. 3d at 754-56.

We believe that the appellate court’s analysis was sound. The

circumstances of this case place it squarely within Mason v. Home

Insurance Co. of Illinois, 177 Ill. App. 3d 454 (1988), and its

progeny. The liability for which Nicor sought indemnification from the

London Insurers did not arise from any inherent defect in the oldstyled gas regulators or the manner in which they were installed in

customers’ homes. Nor did it derive from any systemwide policy or

procedure regarding the methodology employed for removing the

regulators between 1961 and 1978, the period covered by the London

Insurers’ policies. To the contrary, the record indicates that the

methods employed by Nicor for removing the regulators during the

period in question were the same as those ultimately approved by the

court after the Attorney General filed suit against the company in the

year 2000.

Liability was incurred only when mercury happened to spill as an

old-style regulator was being replaced with one of the new mercuryfree units. Such spills were extremely rare. Impermissibly high levels

of mercury contamination were discovered in one-half of 1% of the

homes where physical inspections were undertaken.3

 The spills had no

common cause. Mercury escaped from the regulators under a variety

of circumstances, including unique physical circumstances in particular

homes which required technicians to tilt gas meters in order to remove

them. One spill was reported to have resulted when the Nicor

technician accidently stumbled or tripped. Sometimes technicians were
-21-

careless and neglected to follow Nicor’s safe mercury-handling

procedures. In addition, the spills occurred at different times over a

17-year period in the case of the spills subject to the London Insurers’

policies. No temporal or geographical pattern to these spills was

established, and no claim was made that any particular technician or

group of technicians was responsible for the spills. The technicians did

not even share a common employer. Some were apparently Nicor

employees while others worked for the company’s subcontractors. To

say that each of the 195 spills emanated from a single cause would,

under these circumstances, be completely untenable.

As we have previously discussed, the relevant policies in effect

between 1961 and 1976 define an occurrence as “one happening,” or

a series of happenings arising out of or due to “one event,” while the

policies for 1976 through 1978 speak of “an accident” or “event” or

“continuous or repeated exposure to conditions which result in [injury,

death or physical damage to or destruction of property].” Nothing in

these definitions is materially different from the definitions employed

in the various Illinois appellate court decisions to which the appellate

court looked for guidance, and they are no more ambiguous in this

case than they were in those cases. Giving the words of the policies

their plain and ordinary meaning, as we must, the 195 spills were not

“one happening,” they were not derived from “one event, “ and they

were not all part of “an accident.” Moreover, they cannot be

characterized as involving “continuous or repeated exposure to

conditions which result in [injury, death or physical damage to or

destruction of property].” They were sporadic, not part of an

uninterrupted process, and in no instance evident in the record was

any customer’s home ever subject to more than one exposure to

mercury contamination. The exposure therefore could not have been

“repeated.”

In arguing that the damages attributable to the spills should be

characterized as haven arisen from a single cause, Nicor asserts that

its “liability was not tied to any individual spills.” Rather, it attributes

its liability to the overall costs of investigating and remediating the

spills in response to the legal actions filed against it, costs which it

contends are indivisible. This argument is without merit. The legal

action is not the operative “happening,” “event,” or “accident” giving

rise to liability under the policies. The spills are, and the damages
 4

We further note, parenthetically, that if the remediation order entered in

the underlying legal proceedings were deemed to be the cause of Nicor’s

damages, the London Insurers’ policies would not even be involved. The

coverage provided by those policies ended in 1978. The legal proceedings

against Nicor were not resolved and the remediation order was not entered

until the year 2000. 

-22-

associated with the 195 specific spills covered by the polices can be

and have been specifically identified.4

There is likewise no merit to Nicor’s contention that the spills

should be viewed as the result of a single cause because the individual

claims of its customers were allowed to proceed as a class action and

the attorney general’s action sought redress for all of the spills at the

same time in the same proceeding. Consolidation of individual claims

and the request for comprehensive remedial action in the underlying

litigation relate to questions of litigation efficiency. They have no

bearing whatever on the issue of how many occurrences there were

under the terms of the applicable insurance policies.

We also reject Nicor’s argument that an interpretation of the

policies to find 195 separate occurrences rather than one single

occurrence will somehow deny it the benefit of its bargain. Because

the damages attributable to each of the 195 contaminated homes was

conceded to be less than the applicable deductibles, the determination

that each spill was a separate occurrence and therefore subject to a

separate deductible does mean that Nicor will be able to collect

nothing from the London Insurers. An insurance contract, however,

is not a guarantee of indemnification for every dollar of every loss.

Through deductibles or self insured retentions, a policy holder

may elect to absorb part of the risk for any covered loss in exchange

for reduced premiums. That is precisely what Nicor did here. There is

nothing in the policies themselves or in the circumstances surrounding

the purchase of those policies to suggest in any way that the parties

specifically contemplated that if situations like this one arose, the

losses would be consolidated for purposes of determining the

applicable deductible. In light of the policy language as interpreted in

Illinois, Nicor knew or should have known that such claims would be

viewed as individual occurrences. By electing deductibles in the
-23-

amounts it did, Nicor voluntarily agreed to assume the risk of

absorbing individual claims of the magnitude involved here. What it

apparently misjudged is the total number of such individual claims it

might have to meet at once. While that is unfortunate from Nicor’s

point of view, the company was not an unsophisticated consumer who

was unfairly taken advantage of. It is a major business corporation

with substantial experience and formidable bargaining power. No

principle of public policy authorizes courts to relieve such entities of

the consequences of business calculations merely because those

calculations ultimately prove to be erroneous.

BorgWarner, Inc., who appears in this case as a friend of the

court, concedes that current Illinois case law supports the appellate

court’s determination that each of the 195 spills constituted a separate

occurrence. It also rejects the contention that making each spill

subject to a separate deductible would deny Nicor the benefit of its

bargain. In its view, however, the way in which the cause theory has

been applied in Illinois has become mired in inconsistency and

unpredictability. It argues that this court should address this problem

by refocusing on established principles of contractual construction and

acknowledge that the term occurrence is ambiguous on its face and

under the facts of this case.

We reject BorgWarner, Inc.’s position for three reasons. First, in

making its argument, BorgWarner suggests that insurance policy

provisions should be found ambiguous whenever there is no clear

answer on the face of the policy itself as to how those provisions

should be applied in a particular factual setting. This approach is not

supported by the law of Illinois, as the discussion of insurance policy

ambiguity set forth earlier in this opinion shows. Second, as we have

previously noted, Illinois courts have expressly considered whether

policy provisions such as those at issue in this case were ambiguous

and held that they are not. BorgWarner cites no authority from this

state to support a contrary position. Third, wholly aside from these

considerations, neither Nicor nor the London Insurers take the

position that the term occurrence is ambiguous. This court has held

that we will not address issues raised by an amicus where, as here,

those issues have not previously been raised by the parties themselves.

In re Parentage of M.J., 203 Ill. 2d 526, 542 (2003).
-24-

As with BorgWarner, John Crane, Inc., the other amicus in this

case, agrees that the appellate court was correct in concluding that the

195 mercury spills were separate occurrences under the controlling

policies. It also believes, however, that the cause theory, as presently

applied, has yielded inconsistent results. The remedy it proposes is

similar to BorgWarner’s in that it would have courts refocus their

analysis on the language used in the policies. The difference is that

unlike BorgWarner, John Crane sees no inherent ambiguity in the term

occurrence. Instead, it contends that in evaluating how many

occurrences there are for purposes of coverage under a liability policy,

courts should look first to whether the policy contains a “unifying

directive,” that is, language that purports to aggregate multiple

injuries and claims arising at different times and places into a single

occurrence. Under John Crane’s analysis, the presence of such a

unifying directive would not necessarily result in a finding of a single

occurrence. In the absence of a unifying directive, however, it would

hold that “a single, omnibus occurrence result is never appropriate.”

We express no view on the merits of John Crane’s proposal for

the simple reason that the rule the company suggests is not necessary

to the disposition of this case. A “no unitary directive rule” would

have no bearing on the policies issued by the London Insurers for the

period between November of 1976 and 1978 because those policies

did contain a unifying directive. As John Crane argues, as the

appellate court found, and as we affirm today, the damages attendant

to the mercury spills nevertheless constituted separate occurrences

within the meaning of those policies.

While the polices in effect between 1961 and November of 1976

lacked a unifying directive, having a “no unitary directive rule” would

not affect our construction of those policies either. The existing

analytical framework as developed by the appellate court in Mason v.

Home Insurance Co. of Illinois, 177 Ill. App. 3d 454 (1988), and the

cases that followed already make clear that the dispute before us here

involved multiple occurrences rather than one omnibus occurrence.

Whether we had a “no unitary directive rule” or not, the result in this

case would therefore remain unchanged. Accordingly, any discussion

of the merits of such a rule would be purely academic.

Finally, both BorgWarner and John Crane argue that the

inconsistency they see in the current approach can be remedied by
-25-

adopting a different formulation for applying the cause test than has

been used by our appellate court. BorgWarner argues for a “cause of

injury test.” John Crane speaks of a “last causal element” test.

Although their nomenclature differs, these approaches are premised

on a common idea, namely, that the immediate event giving rise to the

injury should be deemed the cause of an occurrence.

As a preliminary matter, we are unconvinced that the existing

approach has created the inconsistency amici claim. The principal

example of inconsistent results cited by John Crane involves Mason

v. Home Insurance Co. of Illinois, 177 Ill. App. 3d 454 (1988), and

United States Gypsum Co. v. Admiral Insurance Co., 268 Ill. App. 3d

598 (1994), both of which we have discussed in this opinion at length.

According to John Crane, the contaminated patty melts in Mason

were no different than the building material containing asbestos in

United States Gypsum and the two cases should therefore have

reached the same result. Instead, as we have noted, Mason was

deemed to have involved multiple occurrences, while United States

Gypsum found a single occurrence.

Assuming, for the sake of argument, that Mason’s patty melts are

analogous to the asbestos in United States Gypsum’s building

materials, we do not believe that these decisions are at odds. There is

a critical distinction between the cases which John Crane overlooks:

the predicate for the policy holders’ liability. The insured party in

Mason was the restaurant owner whose liability was based on his sale

of the contaminated food to the consumers who patronized his

restaurant. In United States Gypsum, the insured party manufactured

and distributed the building materials, but did not sell them to

consumers or install them in the end-users’ structures. That was done

by others. Accordingly, the insured’s liability was based on its

manufacture and distribution of the materials, not their sale to

consumers and ultimate installation As the appellate court in this case

recognized, the analysis in U.S. Gypsum suggests that if the insured’s

liability had been based on installation of the materials rather than their

manufacture, each installation would have been a separate occurrence,

just as each sale of a patty melt was a separate occurrence in Mason.

362 Ill. App. 3d at 742. The cases are therefore not incompatible.

In any event, as the London Insurers aptly observe, adopting the

alternate formulations proffered by the amici would not alter the result
-26-

in this case. Under any approach to the cause theory, the mercury

spills would be separate occurrences under the policies they issued to

Nicor. Because we perceive no inconsistency in the current approach

to the question as developed by our appellate court and because the

alternative analytical framework advanced by the amici would not

alter our disposition of the present case, we respectfully decline the

amici’s request to use this litigation to recast the law.

CONCLUSION

For the foregoing reasons, the appellate court acted correctly

when it rejected the circuit court’s conclusion that the liability

incurred by Nicor was the result of a single occurrence, reversed the

circuit court’s judgment, and remanded for further proceedings. Under

the liability policies issued to Nicor by the London Insurers between

1961 and 1978, each of the 195 spills did constitute a separate

occurrence, as the appellate court properly held. The appellate court’s

judgment is therefore affirmed.

Affirmed.

JUSTICE BURKE took no part in the consideration or decision

of this case.