<PAGE>


                                                                    EXHIBIT 4.16


                          FIRST SUPPLEMENTAL INDENTURE

         FIRST SUPPLEMENTAL INDENTURE, dated as of June 18, 2002, between
WEIRTON STEEL CORPORATION, a Delaware corporation (the "Issuer" or the
"Company"), and DEUTSCHE BANK TRUST COMPANY AMERICAS (formerly BANKERS TRUST
COMPANY), as trustee (the "Trustee");

                                    RECITALS

         WHEREAS, the Issuer and the Trustee have heretofore executed and
delivered an Indenture dated as of July 3, 1996 (the "Indenture"), pursuant to
which the Issuer has heretofore issued its 11-3/8% Senior Notes due 2004, in the
aggregate original principal amount of $125,000,000 (the "Securities");

         WHEREAS, the Issuer has offered to exchange up to 100% of its
Securities and its 10-3/4% Senior Notes due 2005 for a combination of 10% Senior
Secured Notes due 2008 and Series C Preferred Stock (the "Note Exchange");

         WHEREAS, in connection with the Note Exchange, the Issuer desires to
amend or eliminate certain provisions of the Indenture and have any and all
Defaults or Events of Default waived by the holders of a majority in aggregate
principal amount of the Securities at the time outstanding to the extent
permitted by the Indenture;

         WHEREAS, section 7.2 of the Indenture provides that the Issuer and the
Trustee may, with the consent of the holders of not less than a majority in
aggregate principal amount of the Securities at the time outstanding, enter into
an indenture or indentures supplemental to the Indenture, for the purpose of
adding any provisions to or changing in any manner or eliminating any of the
provisions of the Indenture;

         WHEREAS, all acts and things necessary to amend the Indenture as
aforesaid and to make this First Supplemental Indenture a valid agreement of the
Issuer, in accordance with its terms, have been done; and

         WHEREAS, except as herein expressly otherwise defined, the terms used
herein shall have the same meaning as provided in the Indenture.

         NOW, THEREFORE, in consideration of the foregoing, the parties hereto
agree as follows:

                                    ARTICLE I
                                   AMENDMENTS

         SECTION 1.01.  Deletion of Certain Definitions.

         (a) The following definitions in Section 1.1 of the Indenture are
hereby eliminated and deleted in their entirety as follows:


<PAGE>



         "Acquired Indebtedness"
         "Asset Disposition"
         "Asset Disposition Offer"
         "Attributable Debt"
         "Commodity Agreement"
         "Consolidated EBITDA"
         "Consolidated Fixed Charges"
         "Consolidated Net Income"
         "Consolidated Net Tangible Assets"
         "Consolidated Net Worth"
         "Consolidated Subsidiary"
         "Currency Agreement"
         "Disqualified Stock"
         "Efficiency Program"
         "Indebtedness"
         "Interest Protection Agreement"
         "Investments"
         "Lien"
         "Net Cash Proceeds"
         "Net Income"
         "Offer Amounts"
         "Offer Period"
         "Permitted Indebtedness"
         "Permitted Joint Venture"
         "Permitted Liens"
         "Permitted Payments"
         "Permitted Working Capital Indebtedness"
         "Prohibited Investment"
         "Property"
         "Purchase Date"
         "Refinancing Indebtedness"
         "Restricted Payment"

         SECTION 1.02.  Deletion of Certain Covenants.

         (a)      The following covenants are hereby eliminated and deleted in
their entirety:

                  (i)      Section 3.9. Limitations on Indebtedness.

                  (ii)     Section 3.10.  Limitations on Restricted Payments.

                  (iii)    Section 3.11.  Limitations on Transactions with
                           Affiliates.

                  (iv)     Section 3.12. Restrictions on Disposition of Assets
                           of the Issuer.

                  (v)      Section 3.13.  Limitation on Liens.



                                       2
<PAGE>



                  (vi)     Section 3.14.  Limitations on Sale and Leaseback
                           Transactions.

                  (vii)    Section 3.15.  Limitations on Dividend and Other
                           Payment Restrictions Affecting Subsidiaries.

         SECTION 1.03.  Modification of the Definition of Change in Control.

         (a)      The definition of "Change of Control" in Section 3.16 of the
Indenture is hereby modified to read in its entirety as follows:

         As used herein, "Change of Control" means (i) any sale, lease or other
transfer (in one transaction or a series of transactions) of more than 75% of
the assets of the Issuer to any Person (other than a Wholly Owned Subsidiary of
the Issuer); (ii) a "person" or "group" (within the meaning of Sections 13(d)
and 14(d)(2) of the Exchange Act (other than the 1984 ESOP, the 1989 ESOP or any
other employee benefit plan of the Issuer)) becomes the "beneficial owner" (as
defined in Rule 13d-3 under the Exchange Act) of Capital Stock of the Issuer
representing more than 50% of the voting power of such Capital Stock, unless
such acquisition of beneficial ownership of shares of voting power of Capital
Stock of the Issuer occurs, directly or indirectly, in connection with the
financing of a Permitted Acquisition; (iii) Continuing Directors cease to
constitute at least a majority of the Board of Directors of the Issuer; or (iv)
the stockholders of the Issuer approve any plan or proposal for the liquidation
or dissolution of the Issuer.

         (b)      The following paragraphs are hereby added to the end of
Section 3.16:

         As used herein, "Permitted Acquisition" means any one or more
transactions or series of transactions by the Issuer or a Subsidiary after the
Issue Date, whether effected by merger, consolidation, purchase, lease or other
transfer of assets, Permitted Joint Venture or otherwise, to acquire the
properties and related business (whether through the direct purchase of assets
or of the Capital Stock of the Person owning such assets) of any other Person
(i) where the Person to be acquired has been engaged, or the assets involved
have been deployed, in the business of making, processing or distributing steel
products, including without limitation tin mill products or other coated steel
products, and (ii) the consummation of any such transaction would not otherwise
result in any Event of Default immediately thereafter.

         As used herein, "Permitted Joint Venture" means the interest of the
Issuer in any corporation, association or other business entity of which 50% or
less, but not less than 10%, of the total Voting Stock or other interest is at
the time owned or controlled, directly or indirectly, by the Issuer or one or
more of its Subsidiaries or a combination thereof, provided that (i) such
corporation, association or entity is engaged in the business or businesses of
the Issuer or any related business and (ii) that any interest paid by Issuer or
any Subsidiary of Issuer on any Indebtedness incurred by the Issuer or any
Subsidiary of the Issuer in connection with such ownership interest shall not
exceed the sum of (x) any dividends, other distributions of earnings and returns
of capital received by the Issuer and any Subsidiaries on account of such
ownership interest and (y) demonstrable operating benefits derived by the Issuer
and any Subsidiaries, including cost savings and margin improvements, calculated
on a pro forma basis as determined in good faith by management of the Issuer and
adopted by resolution of a majority of the



                                       3
<PAGE>


independent members of the Issuer's Board of Directors and delivered to the
Trustee in an Officers' Certificate.

         SECTION 1.04.  Modification of Covenants.

         (a) Section 4.1 of the Indenture is hereby modified to read in its
entirety as follows:

         Section 4.1. Event of Default Defined; Acceleration of Maturity; Waiver
of Default. In case one or more of the following Events of Default (whatever the
reason for such Event of Default and whether it shall be voluntary or
involuntary or be effected by operation of law or pursuant to any judgment,
decree or order of any court or any order, rule or regulation of any
administrative or governmental body) shall have occurred and be continuing, that
is to say:

                  (a) default in the payment of any installment of interest and
         Liquidated Damages, if any, upon any of the Securities as and when the
         same shall become due and payable, and continuance of such default for
         a period of 30 days; or

                  (b) default in the payment of all or any part of the principal
         on any of the Securities as and when the same shall become due and
         payable either at maturity, by declaration or otherwise; or

                  (c) failure on the part of the Issuer duly to observe or
         perform any other of the covenants or agreements on the part of the
         Issuer contained in the Securities or in this Indenture for a period of
         60 days after the date on which written notice specifying such failure,
         stating that such notice is a "Notice of Default" hereunder and
         demanding that the Issuer remedy the same, shall have been given by
         registered or certified mail, return receipt requested, to the Issuer
         by the Trustee, or to the Issuer and the Trustee by the holders of at
         least 25% in aggregate principal amount of the Securities at the time
         outstanding; or

                  (d)      [INTENTIONALLY DELETED]

                  (e) a court having jurisdiction in the premises shall enter a
         decree or order for relief in respect of the Issuer in an involuntary
         case under any applicable bankruptcy, insolvency or other similar law
         now or hereafter in effect, or appointing a receiver, liquidator,
         assignee, custodian, trustee, sequestrator (or similar official) of the
         Issuer or for any substantial part of its property or ordering the
         winding up or liquidation of its affairs, and such decree or order
         shall remain unstayed and in effect for a period of 60 consecutive
         days; or

                  (f) the Issuer shall commence a voluntary case under any
         applicable bankruptcy, insolvency or other similar law now or hereafter
         in effect, or consent to the entry of an order for relief in an
         involuntary case under any such law or consent to the appointment or
         taking possession by a receiver, liquidator, assignee, custodian,
         trustee, sequestrator (or similar official) of the Issuer or for any
         substantial part of its property, or make any general assignment for
         the benefit of creditors.




                                       4
<PAGE>



         Then, and in each and every such case, unless the principal of all of
the Securities shall have already become due and payable, either the Trustee or
the holders of not less than 25% in aggregate principal amount of the Securities
then outstanding hereunder, by notice in writing to the Issuer (and to the
Trustee if given by Securityholders), may declare the entire principal of all
the Securities, the interest and Liquidated Damages, if any, accrued thereon, to
be due and payable immediately, and upon any such declaration the same shall
become immediately due and payable. This provision, however, is subject to the
condition that if, at any time after the principal of the Securities shall have
been so declared due and payable, and before any judgment or decree for the
payment of the moneys due shall have been obtained or entered as hereinafter
provided, the Issuer shall pay or shall deposit with the Trustee a sum
sufficient to pay all matured installments of interest and Liquidated Damages,
if any, upon all the Securities and the principal of any and all Securities
which shall have become due otherwise than by acceleration (with interest and
Liquidated Damages, if any, upon such principal and, to the extent that payment
of such interest is enforceable under applicable law, on overdue installments of
interest and Liquidated Damages, if any, at the same rate as the rate of
interest specified in the Securities, to the date of such payment or deposit)
and if any and all Events of Default under the Indenture, other than the
non-payment of the principal of Securities which shall have become due by
acceleration, shall have been cured, waived or otherwise remedied as provided
herein--then and in every such case the holders of a majority in the aggregate
principal amount of the Securities then outstanding, by written notice to the
Issuer and to the Trustee, may waive all defaults and rescind and annul such
declaration and its consequences, but no such waiver or rescission and annulment
shall extend to or shall affect any subsequent default or shall impair any right
consequent thereon.

         (b) Section 8.1 of the Indenture is hereby modified to read in its
entirety as follows:

         Section 8.1. Covenant Not to Merger, Consolidate, Sell or Convey
Property Except Under Certain Conditions. The Issuer will not consolidate or
merge with or into, or sell, lease, convey or otherwise dispose of all or
substantially all of its assets (as an entirety or substantially an entirety in
one transaction or a series of related transactions) to, any Person (other than
a merger with or into a Wholly Owned Subsidiary; provided that such Wholly Owned
Subsidiary is not organized in a foreign jurisdiction) unless: (a) the entity
formed by or surviving any such consolidation or merger (if other than the
Issuer), or to which sale, lease, conveyance or other disposition shall have
been made (the "Surviving Entity"), is a corporation organized and existing
under the laws of the United States, any state thereof or the District of
Columbia; (b) the Surviving Entity assumes by supplemental indenture all of the
obligations of the Issuer on the Securities and this Indenture in form and
substance satisfactory to the Trustee; and (c) immediately after the
transaction, no Default or Event of Default shall have occurred and be
continuing.

                                   ARTICLE II
                                     WAIVER

         SECTION 2.01. Waiver of Defaults. Effective as of the date hereof, to
the fullest extent permitted by the Indenture, the Holders of the Securities
hereby waive any and all Defaults and Events of Default existing as of the date
hereof; provided, however, that all Defaults and Events



                                       5
<PAGE>



of Default with respect to the payment of interest shall only apply to those
Holders that have consented to the execution of this First Supplemental
Indenture.

                                   ARTICLE III
                                  EFFECTIVENESS

         SECTION 3.01. Effectiveness of the First Supplemental Indenture. This
First Supplemental Indenture shall become effective on and as of the date the
counterparts hereto shall have been executed by each of the parties hereto and
shall become operative on and as of the date of the consummation of the Note
Exchange.

                                   ARTICLE IV
                                  MISCELLANEOUS

         SECTION 4.01. Construction with Indenture. All of the covenants,
agreements and provisions of this First Supplemental Indenture shall be deemed
to be and construed as part of the Indenture and vice versa to the same extent
as if fully set forth verbatim therein and herein and shall be fully enforceable
in the manner provided in the Indenture. Except as provided in this First
Supplemental Indenture, the Indenture shall remain in full force and effect and
the terms and conditions thereof are hereby confirmed.

         SECTION 4.02. Responsibility for Recitals. The recitals herein shall be
taken as the statements of the Issuer, and the Trustee assumes no responsibility
for the correctness thereof.

         SECTION 4.03. Successors and Assigns. All the covenants and agreements
in this First Supplemental Indenture contained by the Issuer shall bind its
successors and assigns whether so expressed or not.

         SECTION 4.04. Governing Law. This First Supplemental Indenture shall be
deemed to be a contract under the laws of the State of New York, and for all
purposes shall be construed in accordance with the laws of said State, except as
may otherwise be required by mandatory provisions of law.

         SECTION 4.05. Counterparts. This First Supplemental Indenture may be
executed in any number of counterparts, each of which shall be an original, but
such counterparts shall together constitute but one and the same instrument.

                                      * * *



                                       6
<PAGE>



         IN WITNESS WHEREOF, the parties hereto have caused this First
Supplemental Indenture to be, duly executed, and their respective corporate
seals to be hereunto affixed and attested, all as of the day and year first
above written.

                            WEIRTON STEEL CORPORATION


                            By:  /s/ Mark E. Kaplan
                                 ------------------------------------
                                  Name:      Mark E. Kaplan
                                  Title:     Senior Vice President of
                                             Finance and Administration
ATTEST:

/s/ William R. Kiefer
-------------------------
Name:   William R. Kiefer
Title:  Secretary


                            DEUTSCHE BANK TRUST COMPANY AMERICAS


                            By:  /s/ Irina Golovashchuk
                                ------------------------------------
                                 Name:   Irina Golovashchuk
                                 Title:  Associate
ATTEST:

/s/ Wanda Camacho
-------------------------
Name:    Wanda Camacho
Title: Vice President