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Metal and Nonmetal Mine Safety and Health

Surface Nonmetal Mine
(Sand and Gravel)

Fatal Powered Haulage Accident

Thornhill Sand and Gravel
Thornhill Sand and Gravel Company
Edwards, Hinds County, Mississippi
Mine I.D. 22-00712

August 12, 1999


Donald B. Craig
Supervisory Mine Safety and Health Inspector

Paul E. Scott
Mine Safety and Health Inspector

Terry Marshall
Mechanical Engineer

Originating Office - Mine Safety and Health Administration
Southeastern District
135 Gemini Circle, Suite 212; Birmingham, AL 35209
Martin Rosta, District Manager


On August 12, 1999, William Earl Thornhill, owner-operator, age 49, was fatally injured when a grizzly fell on him as he and a co-worker attempted to dislodge a hangup of material inside a hopper. Prior to the accident they had raised the front of the grizzly and propped it above the hopper so they would have room to work.

The accident occurred because the employees were performing work under a suspended load.

Thornhill had a total of one year mining experience, all at this mine as the owner-operator. He had not received training in accordance with 30 CFR, Part 48.


The Thornhill Sand and Gravel mine, a sand and gravel operation owned and operated by Thornhill Sand and Gravel Company, was located in Edwards, Hinds County, Mississippi. The principal operating official was William Thornhill, owner-operator and victim. The mine was normally operated one 10-hour shift a day, 5-� days a week. Total employment was four persons.

Sand and gravel was excavated from a single bench. The material was hauled by loader to a portable screening plant where it was washed, separated, screened and sized. It was then conveyed to stockpiles. The finished product was sold for use in construction.

MSHA became aware of this plant's existence as a result of the fatal accident. This operation had not been inspected by MSHA prior to the fatality.


On the day of the accident, William Thornhill (victim) and Larry Rogers, plant operator, reported for work at about 7:00 a.m., their normal starting time. Thornhill started the feeder while Rogers used the front-end loader to feed the hopper.

The raw material had a high content of clay which caused it to stick to the sides of the hopper. As the morning progressed, the material built up and would not discharge from the hopper. Thornhill removed links from the reciprocating drive chain in order to improve the discharge of material out of the bottom of the hopper. When this did not work, Thornhill attempted to knock the material down by using a metal fence post but was unable to reach the hangup because the grizzly was in the way. He then put a chain through the grizzly and instructed Rogers to get the loader and position it in front of the hopper. Thornhill connected the other end of the chain to a hook welded on the top lip of the loader's bucket. Rogers then lifted the bucket, raising the front of the grizzly. Thornhill stood the fence post inside the hopper and instructed Rogers to lower the bucket so the weight of the grizzly would rest on the post. Rogers lowered the bucket and Thornhill disconnected the chain from the loader. Rogers parked the loader on the approach ramp, picked up a shovel and proceeded to help Thornhill. As both men were leaning over the hopper to clear the hangup, the grizzly fell, striking them.

Rogers was struck on the head and right arm and knocked unconscious. Thornhill was pinned between the grizzly and the hopper. When Rogers regained consciousness Thornhill was alive. Rogers found Thornhill's cellular phone lying on the ground and tried to call for help but was unable to operate the phone because he could not see clearly. He then went to Thornhill's pick-up truck and drove to a trailer located at the front of mine property, owned by Daniel Plunkett. Rogers told Plunkett that Thornhill had been seriously injured and asked him to get help for himself and Thornhill.

Plunkett was unable to call for help because he did not have a telephone and the cellular phone did not work because they were in a no-service area. Plunkett helped Rogers into the truck and proceeded to take him to the hospital. En route to the hospital, Plunkett met a local fire department emergency technician, flagged him down, and asked him to call for an ambulance for Rogers and for emergency responders to go to the mine site. An ambulance met them and transported Rogers to the hospital where he was treated and later released.

Emergency medical personnel and the coroner arrived at the mine site where Thornhill was pronounced dead as a result of cranial injuries due to blunt force trauma.


On August 12, 1999, Paul E. Scott, Mine Safety and Health Inspector of MSHA's Franklin, Tennessee Field Office, learned of the accident on an 11:00 a.m. television news broadcast while having lunch. Scott contacted MSHA's District Office and was instructed to proceed to the scene and begin the investigation. MSHA conducted an investigation with the assistance of mine employees and the Hinds County Sheriff's Department. There was no designated miners' representative at this mine.


1. The top of the hopper measured 107 inches wide and 68 inches deep and had sideboards on the sides and back. It was about four feet high and tapered on all four sides. The bottom opening measured 23-� inches by 23 inches and was directly above the reciprocating feeder. The hopper was partially below ground level at the approach ramp. The front of the hopper extended 33 inches above ground level. The approach ramp to the hopper was 53 feet long and inclined at a 5 percent grade.

2. The grizzly that covered the hopper was 107-inches wide with grate spacings of approximately 5-inches. It was hinged at the rear of the hopper with two �-inch bolts which allowed the grizzly to be opened at the front. The grizzly weighed approximately 1100 pounds and was not equipped with an integral prop or support mechanism to secure it in the open position.

3. The fence post used to support the grizzly was 73-inches long and 1-inch wide. The post was constructed of T-bar iron.

4. The 3/8-inch chain sling used to raise the grizzly was 15-feet, 7-inches long and made of grade 70 high tensile carbon steel. It was equipped with alloy steel clevis grab hooks at both ends.

5. The front-end loader used to lift the grizzly was a 1988 John Deere Model 644E, four-wheel drive.

6. The weather on the day of the accident was clear and sunny with temperatures around 100 degrees Fahrenheit.


The direct cause of the accident was failure to properly block or secure the grizzly so it could not fall.


Citation number 7772154 was written on September 10, 1999, under the provisions of Section 104(d)(1) of the Mine Act for violation of 30 CFR standard 56.16009:
An owner-operator was fatally injured at this operation on August 12, 1999, when the grizzly he and a co-worker were working under fell, striking the victim. The grizzly, located over the feed hopper of the portable plant had been raised and then propped with a fence post. As the owner and co-worker were leaning over the side of the hopper to clear a hangup, the grizzly fell. Performing work under the grizzly before it was properly secured or blocked was a serious lack of reasonable care constituting more than ordinary negligence and is an unwarrantable failure to comply with a mandatory safety standard.

Related Fatal Alert Bulletin:
Fatal Alert Bulletin Icon FAB99M32


Persons Participating in the Investigation

Thornhill Sand and Gravel Company

Larry Rogers .......... plant operator
Jeffery Ross Vance .......... mobile equipment operator
Hinds County Sheriff's Department
Lt. Dennis Moulder .......... investigator
L. V. Miles .......... deputy sheriff
Kenneth E. McGee .......... crime scene technician
Hinds County Coroner's Office
Bill Chancellor .......... deputy coroner
Daniel P. Plunkett .......... property owner
Mine Safety and Health Administration
Donald B. Craig supervisory mine inspector
Paul E. Scott .......... mine safety and health inspector
Terry Marshall .......... mechanical engineer

Persons Interviewed

Thornhill Sand and Gravel Company
Larry Rogers .......... plant operator
Jeffery Ross Vance .......... mobile equipment operator
Hinds County Sheriff's Department
Lt. Dennis Moulder .......... investigator
Hinds County Coroner's Office
Bill Chancellor .......... deputy coroner
Daniel P. Plunkett .......... property owner