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Volcano Canyon Mining Company
Hazard Gold Mine Asphyxiation

Foresthill, Placer County, California
June 20, 1970
No. Killed 1

USBM Final Investigation Report  (209 Kb)  PDF Format

Rescuer Death

Lester E. Benbow, age 41, schoolteacher, Foresthill Elementary School, was asphyxiated in the Hazard Gold Mine in the early morning of June 20, 1970, when he attempted to rescue Clifford J. Cox, who was overcome in an oxygen deficient atmosphere.  He had no mining experience.  Cox was later transported to the hospital, and reportedly made a complete recovery.

Background Information

The Hazard underground gold mine is located near Volcano Creek, 6 miles southeast of Foresthill, Placer County, California.  The mine was owned by the Volcano Canyon Mining Company, and operated by Clifford A. Osborne, lessee, and Edward Alvey, Richard Ward, and Clifford J. Cox, partners in the mining venture.

The mine had been abandoned for 70 years.  Osborne leased the property in 1964, and rehabilitated the shaft for 128 feet, the bedrock level.  Osborne reportedly had previous mining experience, but his partners had only the knowledge gained since the shaft was reopened December 1969.  The men were employed in other pursuits, and only worked the mine as free time permitted.

Description of Accident

Ward and Cox obtained four "D" oxygen cylinders and some small plastic tubes from a supplier in Placerville, California.  They climbed down the manway, and entered the drift about 8:30 p.m, June 19, 1970.  They planned to prospect the drift, and hoped to reach the face.

The two men entered the oxygen-deficient atmosphere when about 1,900 feet from the station, and proceeded towards the face while breathing oxygen from the cylinders through a small plastic tube.  Cox became exhausted about 2,600 feet from the station, and fell to the floor of the drift.  Ward was weak, and realized he could not remove Cox to a fresh-air source.  He instead returned for help, dropping his cylinders on the way out.  He arrived on surface about 10:30 p.m., alerted Mrs. Alvey, and telephoned for assistance.  Mrs. Alvey telephoned her husband and Osborne who were in Foresthill, and they both rushed to the mine.

Osborne summoned additional assistance and made preparations to rescue Cox.  Alvey climbed down the manway and attempted to reach Cox, but was unable to do so.  Alvey was returning to surface when he met Jack Campbell, an employee of the California Division of Forestry.  Alvey continued to surface and Campbell proceeded toward Cox, but was unable to assist him.  Campbell started towards the surface, and met Kenneth G. Hamilton and James C. Mower, California Division of Forestry, and cautioned them against rescue until additional help arrived.  As Campbell continued towards surface he met Lester Benbow (victim) with some air cylinders and reportedly told him, to wait for more men and additional compressed-air cylinders.

Mower, Hamilton, and Benbow (victim) with Survivair, Scott Air-Pacs, or scuba gear eventually met somewhere near the fresh-air source, and decided to continue to make an effort to rescue Cox.  The three men put on their apparatus and traveled to him.  They were able to move him about 25 feet when their apparatus air supply became exhausted.  Benbow (victim) reportedly said he could breathe better without the mask, which he removed.  He became unconscious almost immediately, and Hamilton became incapacitated a short time later.  Mower with great difficulty returned to the shaft station and telephoned Campbell on surface to report the events.  Mower reportedly was not completely rational.

Gerald W. Quigley, California Division of Forestry, arrived at the mine in the meantime with two compressed-air cylinders attached to his equipment, and one spare.  He reached the accident scene and was able to revive Hamilton, but could not return either Cox or Benbow (victim) to consciousness.  Quigley assisted Hamilton to the surface, where they entered an ambulance about 6 a.m., June 20, 1970, and were transported to Auburn, California.  Both Cox and Benbow (victim) reportedly were breathing when last seen by Quigley about 5 a.m.

Several men arrived at the mine from the Iron Mine Conservation Camp, and a decision was made to connect sections of fiber fire hose to the mine compressor in order to force air into the drift to effect the rescue of Cox and Benbow (victim).  The procedure worked satisfactorily, and Cox was brought to surface about 11:30 a.m., and Benbow (victim) about 1:30 p.m.  Benbow (victim) was pronounced dead by a doctor at the shaft collar.  Cox was transported to the hospital, and reportedly made a complete recovery.

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