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DEPARTMENT OF LABOR MINE SAFETY AND HEALTH ADMINISTRATION Accident Investigation Report Underground Metal Mine Fatal Fall of Rib Sterling Mine Saga Exploration Company Beatty, Nye County, Nevada 26-01503 July 24, 1996 by Stephen A. Cain Mine Safety and Health Inspector Thomas E. Barrington Mine Safety and Health Inspector Mine Safety and Health Administration Western District Vaca Valley Parkway, Suite 600 Vacaville, California 95688 Fred M. Hansen District Manager GENERAL INFORMATION Curtis Ray Pauley, stope miner, age 58, was fatally injured by a fall of ground at approximately 2:30 p.m. on July 24, 1996. Pauley had 36 years of mining experience, the past seven years and eleven months at this operation. He had been trained in accordance with 30 CFR, Part 48. Annual Refresher training was completed June 21, 1996. Peter Cain, vice president of Cathedral Gold Corporation, the principal owner of the property, notified MSHA of the accident at 4:00 p.m. on July 24, 1996. Cathedral Gold maintained an office at the mine site but was not active in the day to day mining operations. The accident scene was secured by MSHA on the day of the accident. An investigation was started on July 25, 1996. The Sterling Mine, consisting of a North Mine work area and a South Mine work area, was a multi-level, underground gold operation located 15 miles south of Beatty, Nye County, Nevada. The mine was operated by Saga Exploration Company of Reno, Nevada. Principal mine officials were Gregory Austin, president and Charles Stevens, mine manager. The mine operated two 8-hour shifts, five days a week, with 30 employees working on the surface and 13 underground. Drilled and blasted ore was mucked with rubber tire mobile equipment in room and pillar stopes. The ore was hauled in LHD's up an incline to surface processing points where it was sized and placed on cyanide leach pads. Gold was recovered through the leaching process and further refining. The last regular inspection of this operation, prior to the accident, was completed on May 1, 1996. Another regular inspection was completed on August 29, 1996. PHYSICAL FACTORS INVOLVED The accident occurred at the North Mine work area, adjacent to a room and pillar stope designated as the 6500 North stope. Access to the stope was through an adit located in the north wall of the company's Ambrose open pit mine. This was the last stope scheduled for development in the North Mine. The stope, in development since June 16, 1996, was in a gold bearing dolomite ore zone with siltstone and shale bedding. The ore dipped 32 to 45 degrees as it extended to the west. The bedded planes of the ore zone varied up to 45 feet in thickness and showed folding from geologic movement. The stope was developed by drilling and blasting six-foot to eight-foot sections of approximately 80 feet of the 6500 North drift's back (roof). The resulting stope ranged from 40 to 50 feet in height. Drilling was performed with a Gardner-Denver model 83 pneumatic drill. Ground support consisted of split sets, wire mesh, and metal matting located throughout the back and ribs. Scaling was being performed as the work progressed. Two openings, referred to as scrams, extended from the 6500 drift to the eastern extremities of the ore body. The scrams were approximately 10 feet high and 10 feet wide. The scram nearest the portal was driven approximately 32 feet and the other approximately 18 feet. A pillar approximately 14 feet wide separated the two scrams. Ore from the scrams, along with material mined from the back, was deposited into the drift, filling it to the level of the scram floors. This material, along with the drift floor, was then removed, creating a 20 foot vertical wall between the drift floor and the scram floor. The victim was drilling into this wall at the time of the accident. Faults within the ore body resulted in fractured, blocky rock structures with joints that dipped into the drift at a 52-degree angle. Clay material between these joints became slippery when exposed to water, promoting the movement of material disturbed by drilling and blasting. Dislodged material tended to move toward the work area. DESCRIPTION OF ACCIDENT On the day of the accident, Curtis Ray Pauley (victim) reported to work at 7:00 a.m., his regular starting time. He arrived at the 6500 stope at 7:30 a.m. and, working alone, began drilling the east rib of the drift in preparation for blasting. At 9:00 a.m. Tom Pennington, shift supervisor, arrived at the 6500 stope and, along with other activities, discussed plans for the drilling of the rib line. At that time Pennington performed a work place examination, noting no adverse conditions. During the morning a number of people observed Pauley, or were in verbal contact with him, where he was drilling in the stope. Pennington last saw Pauley at 1:55 p.m. and then left for the mine office. At 2:30 p.m., Ronnie Fowler, oiler, began servicing the air compressor and generator that supplied compressed air to Pauley's pneumatic drill. She noticed the compressor did not fluctuate during the 30 minutes it took her to complete the task, an indication that the drill was not operating. About 2:55 p.m., Joe Marr, John Holden, and Lindsey Craig, geologists, went to the 6500 stope and saw that a fall of ground had occurred. Muck was piled in the drift and a bent drill steel was protruding from a drill hole. While the others searched for Pauley, Marr returned to the surface to report the roof fall and to inquire if Pauley was out of the mine. Learning that no one had heard from him, Marr, joined by management and mine employees, went back to the 6500 level to assist the other geologists in their search. Pauley was found after about 20 minutes of digging through the fallen material. It appears that he had been drilling into the rib, which rose some 20 feet to the floor of the scram above. As he drilled, broken rock loosened by vibration moved on clay surfaces lubricated by drill water. Suddenly the material dislodged from the drift wall, shoved Pauley across the drift, and covered him with two feet of material. Efforts to resuscitate Pauley began immediately after discovery, without success. Local law enforcement personnel and an ambulance arrived approximately 60 minutes later. Pauley was pronounced dead at 5:17 p.m. by the Nye County Deputy Coroner. CONCLUSION Allowing work to continue in the stope before taking down or supporting hazardous ground conditions was the primary cause of the accident. The miner was also working alone, where he could not be seen, heard, or in communication with others. CITATIONS/ORDERS Order No. 4523380 Issued to Saga Exploration Co. on July 24, 1996 under provisions of Section 103(k) of the Mine Act. Citation No. 4141008 Issued to Saga Exploration Co. on July 24, 1996 under provisions of Section 104(a) for violation of 30 CFR 57.18025. Citation No. 4141010 Issued to Saga Exploration Co. on July 24, 1996 under provisions of Section 104(a) for violation of 30 CFR 57.3200. /s/ Stephen A. Cain Mine Safety and Health Inspector /s/ Thomas E. Barrington Mine Safety and Health Inspector Approved by: Fred M. Hansen, District Manager Related Fatal Alert Bulletin:  [FAB96M31]
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