Massachusetts Fatality Assessment and Control Evaluation Project (FACE) 

MA FACE 

Occupational Fatality Report 

Mechanic Fatally Injured When the Dump Truck Tire 

He Was Inflating Ruptures - Massachusetts 

Release Date: February 26, 2018 Massachusetts Department of Public Health

Investigation: # 15-MA-030-01 Occupational Health Surveillance Program

SUMMARY 

On August 13, 2015, a 38-year-old male mechanic (victim) was fatally injured while inflating a truck 

tire at the maintenance garage of a construction company. The truck was brought back to the company 

garage location when the driver noticed the truck was leaning to the right. As the victim was inflating 

the tire with low air pressure, the tire ruptured. The blast of air from the tire rupturing threw the victim 

15 feet where he then landed on the ground. The driver of the truck immediately placed a call for 

emergency medical services (EMS). The local fire department and EMS arrived at the incident 

location within minutes. The victim was pronounced dead while being transported to the hospital.

Contributing factors identified in this investigation included: not inspecting a tire that had been driven 

on while underinflated before re-inflation; standing within the trajectory of blast forces while inflating 

a truck tire; and not training workers about the specific hazards of working with large truck tires and 

how to identify the hazards associated with filling underinflated truck tires. 

The Massachusetts FACE Program concluded that to prevent similar occurrences in the future, 

employers should: 

 Ensure that employees never position themselves in the trajectory of inflated or partially 

inflated tires while servicing any tire or wheel component; 

 Ensure that tires are properly inspected before inflation if they have been driven on while 

underinflated; 

 Ensure that employees are provided with the necessary tools and equipment in order to safely 

complete any maintenance of truck tires they are expected to perform; and

 Ensure workers are properly trained to identify the hazards of working with large truck tires 

and are trained in safe procedures for working with tires.
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INTRODUCTION 

On August 17, 2015, the Massachusetts FACE Program was alerted by the Occupational Safety and 

Health Administration (OSHA) that on August 13, 2015, a worker was fatally injured while inflating a 

truck tire while working for a construction company. On January 11, 2016, the Massachusetts FACE 

Program Director and a co-worker traveled to the company’s office location and garage. On that visit, 

they met with a company representative to discuss the incident and view the garage, air compressor,

and truck involved in the incident. The police report, death certificate, company information, and the 

OSHA fatality and catastrophe report were reviewed during the course of the investigation. 

Photographs were taken of the incident location, compressor, truck, and remaining tires. 

EMPLOYER 

The employer is a heavy construction contractor that offers multiple services, including trucking and

hauling, heavy equipment rental, and construction demolition material recycling. The company had

been in operation for approximately 10 years at the time of the incident. It employed approximately 15

year-round employees, with additional seasonal and summer employees bringing the total to around

40. Three of these employees, including the victim, were mechanics who maintained the trucks and

equipment. The victim had initially been hired as a part-time worker and had transitioned to working

full-time on the trucks over the summer season.

The typical work hours for the company were 6:00 a.m. to 3:00 p.m. The typical work week was five

days per week, and sometimes a half day on Saturdays during the peak summer season. On the day of

the incident, the victim was working a normal shift. Some employees, including the lead mechanic

who performed equipment maintenance, were represented by a union. Other employees, including the

truck drivers, equipment operators, and most mechanics, including the victim, were not represented by

a union. 

WRITTEN SAFETY PROGRAMS AND TRAINING 

The company did not have a health and safety committee, but did have a written safety program. The 

program was developed by a contracted workplace safety consulting firm and was stored in the main 

office. The program covered general workplace safety topics and some of the types of equipment 

owned and maintained by the company. It did not include details on the hazards of large truck tires 

and their maintenance. On-the-job training related to the job tasks was provided to employees, but this 

training did not specifically include workplace safety and health and the training was not provided in 

Spanish. The company had workers’ compensation insurance as required by law in Massachusetts 

(G.L. c. 152, Sec. 25A). 

Preventive maintenance for the trucks, including adding air to low tires, was conducted on-site by the 

company’s mechanics. Each mechanic had their own personal tools at the site. Major repairs to the 

trucks were performed by a truck dealer. Tire and wheel work was contracted to a few truck tire 

specialists who typically visited the location a few times each week. The tire specialists typically came 

to the site after 3:00 p.m. when the trucks would be back at the lot after the end of the work day. 

The trucks were reportedly inspected each morning using a Department of Transportation, Federal 

Motor Carrier Safety Administration checklist in order to check and record general conditions and 

maintenance issues about the trucks. MA FACE investigators were not able to review records 

indicating whether the truck had been inspected that morning. The low pressure in the tire involved in 
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the incident may not have been identified during a morning check if the truck was not under load and 

the pusher axle was not in use. 

VICTIM 

The victim was a 38-year-old Hispanic male mechanic who had been employed by the company for 

one and a half years at the time of the incident. He had initially been hired for his welding skills and 

held a welding certificate in his native country of El Salvador. He helped to maintain the crushing 

equipment on a part-time basis before transitioning to his full-time position maintaining the trucks. 

The day of the incident, a Thursday, the victim was scheduled to work a full shift of 6:00 a.m. to 3:00 

p.m. The incident occurred around 11:00 a.m., approximately five hours into his shift. The victim 

spoke Spanish and little to no English, and there were reportedly a limited number of co-workers who 

could communicate with him in Spanish. 

INCIDENT LOCATION 

The incident occurred at the company headquarters that included offices, the truck and equipment lot,

maintenance garage, and an area where construction debris was crushed and processed. This location

was a mixed industrial and commercial area in a metropolitan community. The site contained many

parked trucks and other pieces of heavy equipment that were owned by the company and used for

contract work or rental. The garage where the victim worked was accessed through one large bay door

on the rear of the building that faced the parking area (Figure 1). The incident occurred just outside the

bay door where the truck was parked upon returning for service.

EQUIPMENT 

The vehicle involved in the incident was a tri-axle dump truck manufactured in 2003 (Figure 2). The 

company owned and maintained six tri-axle dump trucks. The truck involved in the incident was 

outfitted with tubeless tires mounted on single-piece rims. The tri-axle setup included three axles in 

the rear: two dual-wheel axles plus a single lift/pusher axle that was located just in front of the tandem 

dual axles (Figure 3). The lift axle (Figure 4) was activated by the operator of the truck using controls 

in the cab, and was used to help support a loaded dump bed and assist with stability while turning. The 

lift axle was powered by compressed air and had controls that regulated and balanced the air pressure 

balancing the axle. Increasing the air pressure would push the axle downward, putting the tires in 

contact with the ground to support some of the weight of the load. While the truck was unloaded the 

lift axle would be in a raised position, keeping the tires a few inches off of the road surface as in Figure 

3. 

The tire involved in the incident was a tubeless three-and-a half-foot diameter truck tire with a casing 

consisting of five layers/plies of steel on the tread surface and one layer of steel on the sidewalls. The 

tire was size 385/65/22.5 with a width of just over 15 inches, and was mounted on a 22.5” single-piece 

rim. This size tire is wider than the tires mounted on the other axles of the truck. The extra width 

allows for the tire to support more weight than a standard width tire. When inflated to the 

recommended max 130 psi this tire was rated to support just over 9,900 pounds. It is unknown if the 

tire had been original to the truck, but at the time of investigation a tire of a different brand than the tire 

involved in the incident remained on the opposite side of the axle. 

Also involved in this incident was the air compressor used to inflate the truck tire (Figure 5a). This 

compressor was located inside the garage, near the rear of the maintenance bay. The air supply hose 
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was routed from the compressor to nearby the garage bay door, where a coil of hose was stowed 

(Figure 5b). Additional hose was routed through a hole in the wall of the building (not shown) in order 

to provide an air supply line outside the garage, next to the fuel pump (Figure 5c). The chuck that was 

attached to the air supply line was not at the scene at the time of the site visit but photographs were 

reviewed by FACE investigators. It was a straight dual-head chuck with manual inflation action and 

was activated by pressing the chuck onto the tire valve. The chuck could not be locked on to the valve 

and would have required the victim to hold it in position to inflate the tire. The chuck reportedly 

belonged to the victim, as the mechanics at the company were responsible for supplying most of their 

own tools. 

INVESTIGATION 

The incident occurred around 11:00 a.m. on a Thursday. At the time of the incident it was 77 degrees 

Fahrenheit, with scattered clouds and a seven mile per hour wind. On the morning of the incident, the 

driver of the truck involved in the incident had delivered a load of crushed concrete from the yard to a 

site several miles away and had driven at highway speed. The driver noticed that the truck was leaning 

to the right side on turns when the lift axle was in use. When he returned to the garage at around 11:00 

a.m., after delivering the load, he parked the dump truck outside of the garage near the bay door and 

reportedly described the issue to the mechanic on duty, the victim. Since the driver did not really 

speak Spanish, it is unknown if the victim understood that the tire had been driven on. 

The victim chocked the wheels of the truck and raised the cab. He then reportedly checked the surface 

of the tire by touch and proceeded to check the air pressure. The tire was found to be underinflated. 

The victim proceeded to use the air hose that ran from the compressor in the garage to outside of the 

garage to add air to the tire. As he was inflating the tire he was standing directly next to the tire. It 

was reported that the victim’s stature compared to the height of the tire meant that his chest was 

aligned with the sidewall at the top of the tire. As pressure in the tire increased, the sidewall failed 

near the top of the tire, on the side that was facing away from the truck body. The blast of air struck 

the victim in the chest throwing him 15 feet. He landed face down on the ground, striking his head. 

The truck driver was on the opposite side of the truck, filling the gas tank using the pump that was 

adjacent to the bay door. He heard the explosion and came around the truck to discover the victim 

lying face down on the ground. He called 911 and the lead mechanic. The lead mechanic contacted 

the administrative office to have them also call 911. The town fire department and contracted 

emergency medical services arrived on scene. The victim was transported to a regional level 1 trauma 

center where he was pronounced dead on arrival. 

CONTRIBUTING FACTORS 

Occupational injuries and fatalities are often the result of one or more contributing factors or key 

events in a larger sequence of events that ultimately result in the injury or fatality. The Massachusetts 

FACE team identified the following contributing factors in this incident: 

 not inspecting a tire that had been driven on while underinflated before re-inflation 

 standing within the trajectory of blast forces while inflating a truck tire 

 not training workers about the specific hazards of working with large truck tires 

 not identifying the hazards associated with filling underinflated truck tires 
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CAUSE OF DEATH 

The medical examiner listed the cause of death as multiple blunt force injuries. 

RECOMMENDATIONS/DISCUSSION 

Recommendation #1: Ensure that employees never position themselves in the trajectory of 

inflated or partially inflated tires while servicing any tire or wheel 

component 

Discussion: Large truck tires are a source of hazardous potential energy because of the volume and 

pressure of the air they contain. If this air pressure is released during a tire or wheel failure, the forces 

are enough to seriously injure or kill. Depending what part of the tire or wheel fails, the air blast and 

tire or wheel pieces can project in different directions (Figure 6). Typically when an inflated tubeless 

tire sidewall fails, the forces will project laterally. For this reason it is important to stay clear of the 

sidewall of the tire and wheel at all times while performing work on the tire or wheel. This can be 

done using techniques and tools, such as standing to the front or rear of the tire and using air chucks 

that can be locked on to the inflation valve. (See Recommendation 3.) 

It is likely the sidewall of the tire was compromised when it was driven on under load. With the 

addition of more air to the tire, the sidewall burst in what is termed a zipper failure.1,2 Individual 

strands in the sidewall of the tire stretched and snapped. This led to increased stress on the adjacent 

strands and a cascading failure that ripped through the sidewall of the tire, releasing the pressurized air. 

This type of rupture usually occurs on the top sidewall of the tire as that is the area that undergoes the 

most stretching when the tire is under load. Because the victim was standing facing the tire, the air 

blast struck him in the chest. 

Recommendation #2: Ensure that tires are properly inspected before inflation if they have been 

driven on while underinflated 

Discussion: In this incident, it is unknown if the driver of the truck effectively communicated to the 

victim that the underinflated tire had been driven on while delivering a load that morning. We do 

know that the victim did not deflate and inspect the tire for signs of damage and perform a controlled 

re-inflation of the tire. While the actual low pressure of the tire was not documented, it is believed the 

pressure was below 80% of the recommended pressure. 

Driving on underinflated, overinflated, or overloaded tires can cause damage to the sidewalls that may 

not be visible on the outside surface of the tire. Adding air to tires with damaged sidewalls can cause 

them to fail. For this reason if a tire is driven on while underinflated it is necessary to remove the tire 

from the rim and conduct a thorough inspection before re-inflating. Recommendations and consensus 

standards from the Tire and Rim Association, Tire Industry Association, and Rubber Manufacturers 

Association as well as regulations from OSHA describe that any truck tire that is driven on while it is 

at less than 80% of the recommended inflation pressure should be taken out of service and inspected 

under controlled conditions.3,4,5 This includes deflating the tire, removing the valve stem and 

demounting the tire from the rim, conducting a visual and physical inspection of the tire for defects or 

signs of damage, and re-inflating the tire in a restraining device and under controlled conditions in 

order to observe and listen for any signs of failure. This sort of inspection cannot be performed in the 
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field, so arrangements would need to be made to swap the underinflated tire for a spare tire or tow the 

truck to a garage where the tire can be properly inspected. 

Recommendation #3: Ensure that employees have the necessary tools and equipment in order to 

safely complete any maintenance of truck tires they are expected to 

perform.

Discussion: In order to safely inflate large tires, OSHA requires that the inflation device allow the 

worker to fill a tire while outside of the trajectory of any blast forces (see Recommendation 1). This 

sort of remote inflation can be accomplished by using a chuck that has the ability to lock onto the valve 

on the tire. Also required is either a manual inflation valve with a pressure gauge or a regulator that 

can be set to the desired PSI. These components must be positioned along the air line such that the 

user can perform the inflation while remaining outside of the dangerous trajectory area, so an extension 

hose of suitable length is typically connected between the controls and the chuck. 

In this incident, the chuck and inflator the victim was using did not meet these requirements. It was 

reported that the device used by the victim belonged to the victim and came from his own tool set 

stored at the maintenance garage. It is the norm in some industries for mechanics to supply, maintain, 

and store their own tools at their place of employment. Because the victim and other mechanics were 

responsible for maintaining company-owned vehicles and equipment, it is reasonable for the company 

to supply any specialty tools required to complete their tasks. Whether or not workers supply their 

own tools, it is important for the employer to ensure that the proper tools are used. 

Recommendation #4: Ensure workers are properly trained to identify the hazards of working 

with large truck tires and are trained in safe procedures for working with 

tires 

Discussion: The victim in this incident was not trained on how to properly inspect and inflate tires, nor 

were the victim or the driver trained to understand that once the tire was driven on while underinflated, 

it needed to be taken out of service and inspected. Due to the hazards posed by the potential energy 

stored in large tires, it is important that drivers, mechanics, and other workers be trained to identify and 

understand this hazard. This applies to any large tire, whether it is on a truck or other heavy or 

specialized equipment. OSHA standard 1910.177(c) requires that workers be trained and assessed on 

how to safely service multi-piece and single-piece wheel rims.5 It is equally important that workers 

who service these tires are properly trained on safe procedures and that they understand that tires that 

have been driven on at 80% of the recommended inflation pressure or below could be compromised 

and would need to be removed from service and inspected under controlled conditions before air was 

added. 

All trainings should be performed by a competent person, defined by OSHA as “one who is capable of 

identifying existing and predictable hazards in the surroundings or working conditions which are 

unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective 

measures to eliminate them.” Any training, including but not limited to training on how to perform 

tasks safely, hazard recognition and avoidance of unsafe conditions, needs to be provided in the 

employee’s preferred language. This means the training must be provided in the language(s) and at the 

literacy level(s) of the employees. Retraining should be provided for each employee as necessary. In 

addition, all training should be documented and the documentation should include who provided the 
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training and their qualifications, the content of the training, workers who were trained, and the 

assessments of workers’ comprehension of the training.

REFERENCES 

1. Zipper Rupture. Rubber Manufacturers Association, 2011. 

https://rma.org/wp-content/uploads/ZIPPER-RUPTURE-WALL-CHART.pdf

2. Heavy Vehicles Tire Blowout and Explosion. Instutut de recherché Robert-Sauve en sante et en 

securite du travail (IRSST), 2009. http://www.irsst.qc.ca/files/documents/PublRSST/R-479.pdf

3. Tire Information Service Bulletin: Inspection procedures to identify potential sidewall “zipper 

ruptures” in steel cord radial truck, bus and light truck tires. Rubber Manufacturers Association, 2011. 

https://rma.org/product/tisb-334-inspection-procedures-identify-potential-sidewall-zipper-rupturessteel-cord-radial

4. Code of Federal Regulations, 29 CFR 1910.177, Servicing multi-piece and single piece rim wheels, 

Motor vehicles, U.S. Government Printing Office. 

5. Servicing Single-Piece and Multi-Piece Rim Wheels (booklet). U.S. Department of Labor, 

Occupational Safety and Health Administration,1998, http://www.osha.gov/Publications/wheel/wheelchart-booklet.pdf

Figure 1 – Truck maintenance garage 
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Figure 2 – Truck involved in the incident 

Figure 3 – Tri-axle setup, left side of truck, rear axles 
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Figure 4 – Lift axle, right side of truck (shown with replacement tire) 

Figure 5a – Air compressor Figure 5b – Air supply line 

 
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Figure 5c – Location where air hose and chuck were routed through wall of building and stored 

outside the garage door near the fuel pump 

Figure 6 – Trajectory of typical blast forces during tire/wheel failure: tires laid on the ground 

will direct forces upward; tires on a truck will direct the forces outward from the truck body; 

unmounted tires will direct forces along the axis of the tire