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Accident Investigation Report
Underground Metal Mine

Fatal Fall of Person Accident

Coeur Mine
Silver Valley Resources Corporation
Wallace, Shoshone County, Idaho
ID No. 10-00479

September 12, 1996


Michael J. Drussel
Mine Safety and Health Inspector

Rauswood L. Oliphant
Mine Safety and Health Inspector

Mine Safety and Health Administration
Western District
3333 Vaca Valley Parkway, Suite 600
Vacaville, California 95688

Fred M. Hansen
District Manager


Kenneth Miller, timber repairman, age 49, was fatally injured at 10:11 p.m. on September 12, 1996 when he fell approximately 250 feet down a raise. Miller had worked in the mining industry for 30 years, the past five years at the Coeur Mine. He had received training in accordance with 30 CFR Part 48. Annual refresher training had been conducted in December 1995.

Raymond Latina, office manager, notified MSHA of the accident at 11:30 p.m. on September 12, 1996. An investigation was started the following day.

The accident occurred at the Coeur Mine, an underground copper and silver mine owned and operated by Silver Valley Resources Corporation of Wallace, Shoshone County, Idaho. The principal operating officials were Michael G. Lee, general manager, Larry Erickson, mine manager, and Douglas Yrjana, mine foreman. The mine normally operated two 8-hour production shifts and one 8-hour shaft maintenance shift, five days per week. A total of seventy-five persons were employed at the mine; fifty underground and twenty-five on the surface.

Mining was accomplished by drilling and blasting in timbered raises and stopes. Ore was transferred through timber lined raise chutes, loaded into ore cars, and transported to the production shaft by battery powered electric trams. It was then hoisted to the surface by scroll dump skips.

Prior to the accident, the last regular inspection was completed on September 10,1996. Another regular inspection was completed December 5, 1996.


The accident occurred on the 1900 level at the top of the near 90-degree 424 raise, about 1000 feet from the shaft. The 265-foot raise extended from the 1900 level down to the 2200 level and a short drift connected it to the main haulage drift. The raise was used for ventilation, as a passageway for piping sand tailings, and as a secondary escapeway from the level below.

The four-cap timbered raise had three compartments. The two outside compartments were designed to be used as ore pass chutes. Four-inch by six-inch timber was used on each set to divide the center compartment into a manway and a timber slide. Ten foot long wooden ladders, offset at each landing, ran the length of the manway. The 43-inch by 36-inch timber slide was unrestricted to the 2200 level.

At the third raise set below the collar of the 424 raise, there was an area outside the three compartments, between the raise timber and the hanging wall, which was about 18 inches wide at the top and 30 inches wide at the bottom. A level platform of 2-inch by 12-inch lagging extended the 30 inches between the raise timber and the hanging wall, forming an apron area adjacent to the raise. A 2-inch by 12-inch board, mounted on its side next to the raise set, extended across the apron. The raise set was not completely lagged between the raise timber and the hanging wall on the south side of the middle compartment, allowing access to the apron. Aprons were rountinely installed at each set to catch material sloughing off the hanging wall and to provide an area where equipment and supplies could be stored.

The 3-inch steel victualic-coupled sand pipe on which the victim was working conveyed mill tailings to be used as back filling in mined out stopes and drifts. At the top of the raise, the sand pipe was located in the southeast corner of the timber pass compartment. The line, supported in the raise by steel strap pipe hangers, had been uncoupled during an attempt to restore sand flow. At the separation, the upper portion was stationary and the lower portion had approximately 12 inches of side movement.


On the day of the accident, Kenneth Miller (victim) reported for work at about 4:00 p.m. He worked for senior mine foreman Douglas Yrjana. Miller and his partner, Nick Rounds, were assigned to continue efforts to clear the sand line that was plugged on the 1900 level and in the 424 raise, a problem that had existed throughout the previous shift. By 7:00 p.m. the miners had the sand line cleared to the raise. Miller went to the 2200 level and called the station on the 1900 level for an air purge of the 3-inch sand pipe. After 30 minutes, the line still had not cleared so Miller had the air tuned off and pressure relieved.

Miller climbed up the 424 raise, checking the 3-inch pipe for blockage. At about the same time, Yrjana started down the 424 raise to check on the crew, meeting Miller along the way. Miller and Yrjana agreed that the pipe was probably plugged all the way to the top of the 424 raise and both men proceeded up the raise.

At the first joint of the sand pipe, located 13.5 feet below the 1900 level collar, Miller began to take it apart using a mine fabricated wrench. He was working from the apron area located outside the raise at the same level as the third landing of the manway. When the bolts on the victualic coupling stripped, Miller obtained a hacksaw and began cutting them. Yrjana, located in the manway one set above Miller, could hear the sawing but could not see Miller. Shortly after the sawing stopped, Yrjana heard a sound in the raise below which he described as a low pressure release of water and sand.

When Yrjana looked for Miller and was unable to locate him, he moved down the raise far enough to determine that Miller was not in the area. Yrjana climbed back out of the raise and sent Nick Rounds for help. Yrjana then climbed down the 424 raise and found Miller at the 2200 level.

David Grey, Emergency Medical Technician, examined Miller and was unable to find any vital signs. Dr. Chris Christiansen, from Silverton Medical Clinic, arrived and pronounced Miller dead at 11:28 p.m. Massive trauma was determined to be the cause of death.


The primary cause of the accident was the victim working from an unsafe position in the raise without using a safety belt and lanyard. Apparently, Miller lost his balance when the sand pipe came apart, falling into the opening of the timber slide and down 250 feet to the 2200 level.


The following citations and orders were issued during this investigation:

Order No. 4134436
Issued on September 13, 1996 under provisions of Section 103(k) of the Mine Act:

On September 12, 1996 an underground miner was fatally injured in a fall. This order was issued to insure the safety of persons until the affected areas of the mine could be returned to normal operation and was terminated on September 15, 1996.

Citation No. 7951030
Issued September 14, 1996 under provisions of Section 104(a) for violation of 30 CFR 57.15005:

On September 12, 1996 an underground miner was fatally injured in a fall. He was working on a plugged sand line in a raise, about 250 feet above track level, and was not tied off with a safety belt and line.

/s/ Michael J. Drussel
Mine Safety and Health Inspector

/s/ Rauswood L. Oliphant
Mine Safety and Health Inspector

Approved by: Fred M. Hansen, Manager, Western District

Related Fatal Alert Bulletin:
Fatal Alert Bulletin Icon [FAB96M35]