Skip to content

Metal and Nonmetal Mine Safety and Health

Accident Investigation Report
Surface Nonmetal Mine

Fatal Slip/Fall Accident

Old Page Mill Tractor Service


Langley Hill Quarry (mine)
Langley Hill Quarry (company)
Woodside, San Mateo County, California
ID No. 04-00170

March 12, 1998


Delbert Curtis
Mine Safety and Health Inspector


Curtis Petty
Mine Safety and Health Inspector (Trainee)

Mine Safety and Health Administration
Western District
2060 Peabody Road - Suite 610
Vacaville, California 95687

James M. Salois
District Manager


Kerry Horn, customer and truck owner, age 51, was fatally injured at about 1:30 p.m. on March 12, 1998, when he apparently fell from the scalehouse handrail or the rear of his truck onto the concrete portion of the scale pad. He died three days later. Horn had been a truck driver for about 32 years, the past two years hauling crushed stone from local mines. Horn had not received training in accordance with 30 CFR Part 48.

MSHA was notified at 3:40 p.m. on the day of the accident by a telephone call from Michael Dempsey, co-owner of the Langley Hill Quarry. Initially, it was reported that the injuries were not life threatening. An investigation was begun on March 25, 1998.

The Langley Hill Quarry, an open pit crushed limestone operation, owned and operated by Langley Hill Quarry company, was located about ten miles west of Woodside, San Mateo County, California. The principal operating official was Michael Dempsey, partner. The mine was normally operated one, 8-hour shift a day, five days a week. Total employment was two persons.

Limestone was drilled and blasted from multiple benches in the quarry. Broken material was fed into a crusher by front-end loader, then transported through the plant for secondary crushing and screening. The finished product was loaded from stockpiles into over-the-road trucks to be used for construction aggregate.

At the time of the accident, Old Page Mill Tractor Service was hauling material from Langley Hill Quarry for grading driveways in the local area. The principle operating officials were the victim and John Luetscher, partners.

The last regular inspection of this operation was completed on September 2, 1997. Another inspection was conducted following this investigation.


The accident occurred at the scalehouse where trucks were weighed. The scale was about 70 feet long and 10 feet wide and was located adjacent to a scale house/office trailer.

At the time of the accident, the rear of the victim's truck was parked about twenty-four feet from the front of the scale. The truck was a General Motors, Model 70, five-ton capacity, two-axle dump truck which weighed about 25,000 pounds.

The weather was rainy and cool and the victim was wearing a coat at the time of the accident.


On the day of the accident, Kerry Horn (victim) was hauling material from the Langley Hill Quarry to a local work site. At about 1:00 p.m., Horn's truck was loaded with material and he drove to the scale nearby to be weighed. Michael Dempsey, loader operator/weigh master and partner in Langley Hill Quarry, loaded another truck driven by Brian Handley, before stopping to weigh the two trucks. Dempsey saw Horn at the scale standing behind his truck with his hands behind his back waiting to be weighed.

Moments later, after loading the second truck, Dempsey rode the short distance to the scale in Handley's truck. As they approached the scale, they saw Horn lying on the concrete pad, unresponsive and bleeding from the nose and mouth. Apparently, he had fallen from the truck or handrail and was lying face down about one foot from the right side tire flaps.

Dempsey asked Handley to call the local 911 telephone number for emergency assistance. Horn was still breathing and Dempsey administered first aid as instructed over the telephone. Local authorities arrived a short time later. Emergency medical assistance was provided and the victim was transported to a hospital by a life-flight helicopter.

Medical records showed a blood alcohol level of 0.04%. Horn died in the hospital at 6:00 p.m. on March 15, 1998 as a result of multiple facial and skull fractures.


It could not be determined why or exactly from where Horn fell. There was no apparent need for him to have climbed onto the handrail or the rear of the truck.

Related Fatal Alert Bulletin:
Fatal Alert Bulletin Icon FAB98M18