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MSHA - Fatal Investigation Report

Metal and Nonmetal Mine Safety and Health


Underground Metal Mine

Fatal Fall of Ground Accident

November 9, 1999

Momi Mine
Momi Mining Company
Silver Springs, Lyon County, Nevada
ID No. 26-02401

Accident Investigator

Richard M. Wilson
Mine Safety and Health Inspector

Originating Office
Mine Safety and Health Administration
Rocky Mountain District
P.O. Box 25367, DFC, Denver, Colorado 80225-0367
Irvin T. Hooker, District Manager


On November 9, 1999, Bruce C. Kempffer, miner and owner, age 67, was found in the underground portion of the mine. A fall of ground had occurred fatally injuring him. The coroner's report listed the probable cause of death as asphyxiation.

Kempffer had a total of 4 years experience as an underground miner prior to opening this mine. He had operated and worked at this operation on an intermittent basis since filing the BLM claim in 1979.

The accident occurred because the ground had not been supported. Kempffer had not received training under Part 48.


The Momi Mine, a two level underground gold mine, located near Silver Springs, Lyon County, Nevada, was owned and operated by Bruce C. Kempffer. The work schedule for the mine could not be ascertained. Kempffer had worked the mine on an intermittent basis since 1979. Total employment at the time of the accident was two employees.

Gold-bearing ore was drilled, blasted and hand-loaded into five gallon plastic buckets. These buckets were carried to the surface where the ore was sorted by hand. There were no milling facilities located at this mine and it was unknown where the hand-picked ore was taken after it was removed from the mine property. MSHA had not been notified of the commencement of mining at this operation. The mine had not been inspected by MSHA.


The exact time and date of the accident was unknown, but it was believed to have been at least six to eight weeks before Bruce Kempffer (victim) was found on November 9, 1999. The victim was located about 40 to 45 feet inside the mine. The grade at the area of the accident was a slight decline of about six percent.

Approximately five to six tons of material had fallen and covered most of the victim. The material consisted of various sizes and included a large 16-inch by 16-inch by 4-inch thick slab. Kempffer had been working in an open stope, but his activities at the time of the accident could not be determined. A copper pipe measuring 6 feet by 1/2-inch diameter and some unused explosives were found laying next to the victim. An Ingersoll Rand rotary hammer (not a jackleg) with an air hose attached was laying on the left side of the drift about 20 feet inside the mine.


MSHA was notified of the accident at 7:00 a.m., on November 9, 1999, by a telephone call from Skip Flannigan, Nevada state mine inspector, to William Wilson, assistant district manager. An investigation was started that day. An MSHA investigator traveled to the mine site and conducted a physical inspection of the accident site, interviewed two Lyon County deputy sheriff's and reviewed documents concerning the victim. The Lyon County Sheriff's Department and the State of Nevada Division of Industrial Relations Mine Safety and Training participated in the investigation.


• Friends of Kempffer contacted the Lyon County Sheriff's Department and told them that Kempffer had not checked in with them in over two months. Deputy Tom Van Dalinda was dispatched to the mine area to check on Kempffer. Deputy Robert R. King of the Lyon County Emergency Services , heard a radio dispatch and responded to the mine site to assist deputy Van Dalinda. The dispatcher contacted the State of Nevada Mine Enforcement and notified them of the accident. Upon arrival at the mine, Nevada Mine Enforcement personnel entered the mine and found the victim under the fallen material.
• The fall of ground accident occurred in the only active working area of the mine. Kempffer's body was located approximately 45 feet inside the mine portal, on a six percent decline. The main portal entrance to the underground mine was approximately 15 feet wide and 12 feet high. The mining method used in this mine involved opening a stope approximately 15 feet wide by 6 feet wide by 12 feet high from the main drift. Ground support was not used in the mine.
• The ore mined in the stope consisted of quartz and hematite on the hanging wall and granite and limestone on the footwall. The total overburden above the underground mine varied from 5-10 feet.
• A decline drift, above the main entrance portal from the east side, was used for storage of explosives (stick powder) and electric blasting caps. The caps were stored in metal ammo cans beside the explosives. Light track rail and ties were also stored in the same area. The decline drift was approximately 30 feet long, 6 feet wide and 6 feet high. The end of the drift connected with the open workings of the active stope.


The root cause of the accident was the failure to install ground support where needed. Contributing factors were the failure to properly examine and test ground conditions prior to the commencement of work.

Related Fatal Alert Bulletin:
Fatal Alert Bulletin Icon FAB99M48


Persons Participating in the Investigation

State of Nevada
Edward M. Tomany . . . . . . . . . . . . . . . . . . . . . .chief administration officer, mine inspector
Skip Flannigan . . . . . . . . . . . . . . . . . . . . . . . . . .assistant chief administration officer, mine inspector
Lyon County Sheriff's Department
Tom Van Dalinda . . . . . . . . . . . . . . . . . . . . . . . investigator, deputy
Robert R. King . . . . . . . . . . . . . . . . . . . . . . . . .emergency services coordinator, deputy
Mine Safety and Health Administration
Richard M. Wilson . . . . . . . . . . . . . . . . . . . . . mine safety and health inspector


Persons Interviewed

Family Member
Shawn Tracer Nesteby . . . . . . . . . . . . . . . . . . . . . .step-daughter
Lyon County Sheriff's Department
Tom Van Dalinda . . . . . . . . . . . . . . . . . . . . . .investigator, deputy
Robert R. King . . . . . . . . . . . . . . . . . . . . . . . emergency services coordinator, deputy

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