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District 9

Accident Investigation Report
(Surface Coal Mine)

Fatal Powered Haulage Accident

Buckskin Mine (48-01200)
Triton Coal Company
Gillette, Campbell County, Wyoming

July 2, 1998


David W. Elkins
Mining Engineer

Originating Office: Mine Safety and Health Administration
P.O. Box 25367, Denver, Colorado 80225-0367
John A. Kuzar, District Manager


On Thursday, July 2, 1998, Louis Lopez, mine manager, radioed Roy Hough, mining technician (victim), that Lopez would relieve Hough of driving a 190-ton haul truck while Hough ate lunch. Hough pulled the haul truck onto the backfill dump area, exited the truck, and walked to the right side of the truck to wait for Lopez. Lopez arrived in a half-ton pickup truck and parked adjacent to the right side of the haul truck. Lopez left the engine running and watched as Hough entered the pickup truck. Lopez entered the haul truck and sounded a two-horn signal. Both the pickup truck and the haul truck moved forward simultaneously. The haul truck ran over the cab and hood of the pickup truck causing fatal crushing injuries to Hough.


The Buckskin Mine is a surface sub-bituminous coal mine located 12 miles north of Gillette, Wyoming. The mine opened in 1981. It is owned by Triton Coal Company, a subsidiary of Bluegrass Coal Development Company.

The mine has one active pit. The 160-foot thick overburden is blasted and then removed with a P&H 2800 shovel with a 42 cubic yard bucket and with a P&H 2300 shovel with a 28 cubic yard bucket. The overburden is loaded into Unit Rig MT-3700 haul trucks and Euclid R-190 haul trucks for transport to dump sites. The Anderson and Canyon coal seams, with a combined thickness of 80 to 100 feet, are blasted. The coal is then loaded into Euclid R-170 haul trucks by a Bucyrus Erie 290B shovel, and is transported to the truck dump. The coal is then sent by conveyor belt to two crushers and finally to the unit train loadout.

The mine has 150 employees, including 120 surface miners, and has a daily production of approximately 70,000 tons. The mine works two 12-hour shifts, seven days per week.

The last regular safety and health inspection at this mine was completed by the Mine Safety and Health Administration (MSHA) on March 10, 1998.

The principal officials at the mine are:

Terry WilkersonActing General Manager
Herb PridgeonActing Operations Manager
Richard BurnsSafety Coordinator


On Thursday, July 2, 1998, at 4:50 a.m., Louis E. Lopez, mine manager, arrived at the mine and conducted an examination of the work areas. At 6:00 a.m., the day shift miners began work. Roy Wayne Hough, mining technician, was assigned to his usual task of operating a haul truck. He drove a Unit Rig model MT-3700 haul truck, serial number 127, company number 88, which had a capacity of 190 tons. Hough's assignment was to receive overburden from the P&H 2800 shovel located in the overburden 5 area, and then to transport the overburden to the backfill 2 bench dump area.

Production proceeded normally throughout the morning. At approximately noon, Hough drove from the shovel to the dump and dumped his load. Afterward Hough was seen in the vicinity of the lunch trailer searching for someone to drive his truck for him while he ate lunch. Finding no one at the lunch trailer, Hough drove to the fueling area to refuel the haul truck. At approximately 12:15 p.m., Lopez drove a front-end-loader past the fueling area and saw Hough completing the fueling process. As Lopez was parking the front-end-loader, he saw Hough drive by. Lopez radioed Hough and told him to stop so that Lopez could drive for him during lunch. Lopez then got into his Chevrolet K1500 pickup truck to drive to where Hough had stopped.

Paul Douglas, mining technician, who had been driving a Unit Rig model MT-3700 haul truck, company number 86, was parked on the backfill 2 bench dump. As Douglas was walking around haul truck 86 to examine the struts, he saw Hough park haul truck 88 on the dump about 50 feet away from haul truck 86. At approximately 12:23 p.m., Lopez drove his pickup truck onto the dump. By then, Hough had climbed off haul truck 88 and was standing on the right side of the truck near the gas tank. Lopez parked the pickup truck so that the front of the pickup truck was positioned slightly behind, and approximately 15 feet away from the right front tire of haul truck 88. Lopez placed the pickup truck in neutral, set the parking brake, and exited the truck. He watched as Hough placed his lunch bucket in the back of the pickup truck and got in the truck. Lopez then walked to the front of haul truck 88 where he saw Douglas signal to him that the struts on haul truck 86 were okay. Lopez climbed into the cab of haul truck 88, fastened his seat belt, and, at 12:25 p.m., sounded the horn twice to indicate that he intended to move forward. At the same time, Douglas sounded his horn twice, then he began to move forward before Lopez moved truck 88 forward. Approximately 3 seconds elapsed from the time Lopez sounded his horn to the time when he began moving because there were three brakes that had to be disengaged. Lopez looked to see that the area was clear and then began driving forward in a straight direction when he felt two bumps. He immediately stopped the haul truck, got out of the cab, and looked down off the right side. He then climbed down and walked around the left side to the back of the haul truck where he could see that the haul truck had run over the cab and hood of the pickup truck.

At 12:26 p.m., Lopez radioed to summon the mine rescue team, to request a forklift to extract Hough, and to declare a mine emergency. At 12:27 p.m., Lopez requested that an ambulance be called to the scene. When the mine rescue team arrived, Hough was unconscious and wedged inside the pickup truck. Hough was given mouth-to-mouth resuscitation while the forklift and a come-along were used to free him. When the ambulance and a fire truck arrived at 12:45 p.m., Hough had been extracted from the pickup truck. Hough was transported to Campbell County Memorial Hospital where he succumbed to his injuries at 1:24 p.m. Lopez was hospitalized following the accident due to a significant increase in his blood pressure and for chest pains.


  1. Haul truck 88 was examined after the accident. The steering, brakes, horn, and backup alarm were all in proper working condition.

  2. The pickup truck damaged in the accident was a 1996 Chevrolet K1500 with 4 wheel drive and one-half ton payload capacity. The truck belonged to Louis E. Lopez and had Wyoming license plate number 17 775 AL, and vehicle identification number 1GCEK19R2TE144762.

  3. Due to the severe damage to the pickup truck, physical factors regarding gears, brakes, operating condition, horn, etc. could not be determined. The owner of the pickup, Louis Lopez, stated that the truck was in excellent mechanical condition with no defects. He had replaced the clutch and completed other repairs approximately one month prior to the accident.

  4. There were no marks in the dirt to indicate that the pickup truck spun its wheels in an attempt to elude the haul truck.

  5. There were no extraneous materials found in the cab of either the haul truck or the pickup truck that could have contributed to the accident.

  6. Red paint, similar to the color of the pickup truck paint, was found on the right front tire, the right rear tires, and the right side engine access steps of haul truck 88. Shards of glass were found embedded in the right front tire of the haul truck.

  7. The dents across the hood of the pickup truck matched the shape and size of the dual rear wheels of the haul truck.

  8. The windows and mirrors of the haul truck were relatively clean and unbroken. The mirrors were properly adjusted for visibility behind and to the side of the haul truck.

  9. The haul truck was not loaded at the time of the accident. The weight of the unloaded truck was 759,000 pounds.

  10. The ground in the vicinity of the accident was relatively level and dry.

  11. Louis Lopez obtained a new pair of prescription glasses in March, 1998.

  12. Paul Douglas stated that, from inside the cab of haul truck 86, with its engine running, he could hear the two horn signals that Lopez gave from truck 88.

  13. A flag pole was mounted on the pickup truck behind the cab. A red flag was attached to the top of the flag pole. This flag was 13.5 feet above the ground and was intended to decrease the blind spot of the haul trucks so that the drivers of the haul trucks could more easily see the pickup truck. However, due to the location of the retarder box on the haul truck, the flag on the pickup truck was not visible off the right side of the haul truck until the pickup truck was 67 feet away from the haul truck.

  14. Each of the tires of the Unit Rig MT-3700 haul truck, company number 88, was 12.5 feet in diameter by 3 feet wide.

  15. The haul truck had received a mechanical and electrical examination by a mining technician on June 24, 1998.

  16. The safety reports for haul truck 88, as completed by the haul truck operators during the previous 12 shifts, did not indicate any significant safety problems with the haul truck.

  17. The day shift work hours are 6:00 a.m. to 6:00 p.m.

  18. The use of alcohol or drugs was not a factor in the accident.

  19. In May, 1998, within a three day time period, two incidents occurred at this mine in which pickup trucks were struck by large mining equipment (shovel and haul truck). No injuries occurred in either case. Within 15 minutes of the second incident, Richard Burns, safety coordinator, held a safety meeting to try to prevent these types of incidents. He showed a video which emphasized the importance of not parking a pickup truck in the blind area of a haul truck. Both Hough and Lopez attended the meeting.

  20. The day of the accident was sunny and warm. It had not rained that day.

  21. After the accident, the front tires of the pickup truck were found to be pointed as though the truck were traveling in a straight direction.

  22. Testimony indicated that Hough was not hard of hearing, and Lopez stated that the am/fm radio was not turned on when he exited the pickup truck. Therefore, Hough should have been capable of hearing the horn signals of the haul trucks.

  23. Prior to his promotion to mine manager on December 4, 1996, Lopez had over 7.5 years of experience operating heavy equipment, including haul trucks, at this mine.

  24. Lopez and Hough had both received training as required by 30 CFR, Part 48.

  25. Immediately following the accident, the haul truck was stopped so that its rear tires were approximately 15 feet away from the pickup truck. Afterward, the haul truck was moved away from the scene to facilitate the rescue efforts.

  26. Tire prints at the scene indicated that haul truck 88 drove in a straight direction prior to and during contact with the pickup truck. This coincides with the testimony of Lopez.

  27. The pickup truck did not have a two-way radio in it and Hough did not carry a portable two-way radio. Thus, although the haul truck had a two-way radio in it and Lopez carried a portable two-way radio, it was not possible for Hough and Lopez to communicate via the radio immediately prior to the accident.

  28. An autopsy, performed by the coroner of Campbell County, Wyoming, indicated that there was "no evidence to indicate that the deceased came to his accidental death by unlawful means".

  29. Considering where the pickup truck had been parked, the haul truck could not have contacted the pickup truck unless the pickup truck had been driven forward. It could not be determined why Hough remained parked in the pickup truck for the approximately two minutes that elapsed from the time he entered the pickup until the accident. It also could not be determined why Hough drove forward into the path of the haul truck instead of steering to the right to reach his intended destination of the lunch trailer.


The accident occurred when the haul truck drove over the cab and hood of the pickup truck causing fatal crushing injuries to the driver of the pickup truck.

The contributing factors to the accident were:

  1. The pickup truck was parked in the blind spot of the haul truck.

  2. The haul truck driver did not ensure that all persons were clear before moving the haul truck.

  3. When he was in the pickup truck, the victim did not have a radio for communication with the haul trucks.

  4. The mine did not have an area designated and designed for the safe switching of haul truck drivers.


A section 103(k) order, number 3563117, was issued following the accident to ensure the safety of the miners.

A section 104(a) citation, number 3563118, was issued because the haul truck operator did not ensure that all persons were clear before moving the haul truck. This is a violation of 30 CFR 77.1607(g).

Submitted by:

David W. Elkins
Mining Engineer

Approved by:

Irvin T. Hooker
Acting Assistant District
   Manager for Inspections

John A. Kuzar
District Manager

Related Fatal Alert Bulletin:
Fatal Alert Bulletin Icon FAB98C15