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MAI-2010-09
UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION

METAL AND NONMETAL MINE SAFETY AND HEALTH

REPORT OF INVESTIGATION

Underground Metal Mine
(Gold)

Fatal Explosives Accident
May 28, 2010

Discovery Day Mine
Gold Run Enterprises LLC
Forks of Salmon, Siskiyou County, CA
Mine ID No. 04-05222

Investigators

James Fitch
Supervisory Mine Safety and Health Inspector

Brad Breland
Supervisory Mine Safety and Health Inspector

Tom Lobb
Physical Scientist

Originating Office
Mine Safety and Health Administration
Western District
2060 Peabody Road, Suite 610
Vacaville, CA 95687
Wyatt S. Andrews, Acting District Manager




OVERVIEW

On May 28, 2010, James S. Bennett, supervisor, age 62, died when an unplanned delayed initiation of explosives occurred. The victim and Michael Engelke, miner, entered a blast area to check it. When they were within 25 feet of the face, the misfire detonated and both miners were struck by fly rock from the blast. Engelke was injured, hospitalized, and later released.

The accident occurred because management failed to ensure that policies and procedures to protect miners in blast areas were followed. The procedures did not ensure that miners did not return to the blast site for at least one hour after the suspected burning stopped.

GENERAL INFORMATION

The Discovery Day Mine, an underground gold mine operated by Gold Run Enterprises LLC, is located near Forks of Salmon, Siskiyou County, California. The principal operating official is Patrick A. Fagen, manager. The mine normally operates one 10 hour shift per day, for 10 to 14 days, with one to two weeks between rotations. Total employment is 14 persons.

Gold bearing ore is drilled and blasted from stopes in the mine. The broken rock is transported by a haul truck to the primary crusher where it is crushed and processed. The finished product is sold to commercial industries.

The last regular inspection was completed at this mine on February 26, 2010.

DESCRIPTION OF THE ACCIDENT

On the day of the accident, James S. Bennett (victim) started work at 7:00 a.m., his normal start time. Bennett went to the 13 east drift with Ralph Kuntz and Michael Engelke, miners, to set up to drill the next round in the heading. The crew drilled the round before lunch.

After lunch, Bennett and Kuntz loaded the round. Kuntz then left the area. About 8:00 pm, Bennett lit the fuse and went to the inby bend in the 13 east drift to wait for the round to detonate. Engelke went further down the drift toward the 72 crosscut. After the blast detonated, Engelke walked to Bennett and they discussed that the blast did not sound right.

Bennett and Engelke waited for about 15 to 20 minutes before reentering the area. Bennett was walking in the center of the drift, slightly ahead of Engelke. When Bennett was about 20 to 25 feet from the face, several of the still loaded holes detonated. Both Bennett and Engelke were struck by broken rock and debris from the blast.

They left the 13 east heading and started out of the mine, with Bennett assisting Engelke. Bennett and Engelke met Kuntz in the B9 crosscut, who then walked with them out of the mine. The victims were treated and then life-flighted to a hospital in Redding, California, where Bennett died on May29, 2010. The cause of death was attributed to blunt force trauma. Engelke was hospitalized and later released.

INVESTIGATION OF THE ACCIDENT

On May 28, 2010, the Mine Safety and Health Administration (MSHA) was notified at 11:08 p.m. PST by a telephone call from manager Patrick Fagen to MSHA's emergency call center. Brad Breland, supervisory mine safety and health inspector, was notified and an investigation started the next day. An order was issued under the provisions of section 103(j) of the Mine Act to ensure the safety of the miners. A citation was issued for late reporting.

MSHA's accident investigation team traveled to the mine, conducted a physical inspection of the accident scene, interviewed employees, and reviewed conditions and work practices relevant to the accident. MSHA conducted the investigation with the assistance of the state of California Occupational Safety and Health, Mining and Tunneling Unit (Cal/OSHA), the Siskiyou County Sheriff's Bomb Squad, and the Bureau of Alcohol, Tobacco, Firearms, and Explosives (BATFE).

DISCUSSION

Location of the Accident

The accident occurred at the face of the 13 east drift. The toe of the muck pile was approximately 17 feet from the face. The floor of the drift was wet and muddy. Individual rocks ranging up to approximately 6 inches wide by 6 inches long and 6 inches thick were observed on the floor past the toe of the muck pile. The upper 3 feet of the face was visible above the muck pile. The blasted face was deeper on the left side than the right. Shock tubes from the detonators, used when the face was loaded, were observed in two holes. Both of these holes were to the right of the center line of the face.

13 East Drift

The 13 east drift extended northeast off the 72 crosscut drift. It was being developed to intersect with the #1 and #2 veins which run northwest to southwest. The drift was 8 feet high and 8 feet wide. Ground control consisted of a mixture of timber, split set, point anchor bolts, and mats. Ground water had been encountered in the face when the lower holes were drilled.

Explosive Product Involved With the Accident

The explosives and detonators used in the blast were as follows:
ANFO (Ammonium Nitrate Fuel Oil) - Alpha Mix Explosives Blasting Agent 1.5D, EX-9311228 NA 0331
Powder - "Dyno." AP Plus 1 � X 8 inch emulsion based 1.1D explosive 18FE04J1-29611
Explosive Boosters - Dyno Nobel Red Stingers 10 gram cast boosters 1.1D
Detonation Cord - DYNO Special 25, UN0065 1.1D
Detonators - "DYNO LP." Nonelectric 1.1B 1 - 11 period delays with 12 foot lead-ins.