1971 — June 24, tunnel under construction gas explosion, CA Water Project, Sylmar, CA-17

–17 Ferrara, Grace M. The Disaster File: The 1970’s. New York: Facts on File, 1979, p. 102.
–17 National Fire Protection Association. The 1984 Fire Almanac. 1983, p. 139.
–16 NFPA. “Multiple-Death Fires, 1971,” Fire Journal, Vol. 66, No. 3, May 1972, p. 64.

Narrative Information

Ferrara: “L.A. tunnel blast. Seventeen workmen drilling a water tunnel 250 feet below the Los Angeles suburb of Sylmar were killed June 24 when a fire, sparked by an explosion, roared through the shaft. The blast was the second in two days. Four men were injured in the first.

“Spokesmen for the Lockheed Shipbuilding and Construction Co., (a subsidiary of the aircraft firm), the builders of the 5.5 mile tunnel, said inspectors of the State Division of Industrial Safety had examined the tunnel after the first blast and safety precautions had been tightened.” (Ferrara, Grace M. The Disaster File: The 1970’s. New York: Facts on File, 1979, p. 102.)

National Fire Protection Association: “[A]…blast in a tunnel under construction (to be used for water supply for the Southern California area) took the lives of 16 workers in Sylmar, California, on June 24. This explosion is…believed to have been the result of ignition of methane by the drilling equipment (mole). The day before the explosion four workers had been injured in a flash fire, after which, reportedly, the tunnel atmosphere was monitored constantly.” (NFPA. “Multiple-Death Fires, 1971,” Fire Journal, Vol. 66, No. 3, May 1972, p. 64.)

Newspaper

June 24, United Press International: “Sylmar (UPI) — A natural gas explosion flared through a water tunnel today, suffocating trapped miners in one of the worst underground disasters in California history. At least one man survived. Four bodies were retrieved, and 13 other miners were presumed dead in the tunnel. A fireman said five bodies could be accounted for by ‘arms and legs protruding from the rubble.’

“It was the third disaster to strike a section of the multibillion-dollar California Water Project, the most complex water work ever attempted, and the second explosion in the Sylmar tunnel in two days. The explosion set part of the tunnel afire and it was still burning almost 12 hours later, firemen said.

Rail cars rumbled to the surface bearing bodies of the dead, as weeping relatives looked on from a nearby hill. The miners probably died of asphyxiation, as the gas burst into flames and consumed all oxygen in the area, police said. Rescue workers had trouble seeing in the smoke and dust that followed the blast shortly after midnight. They were limited by their oxygen tanks to 30 or 60 minute stays in the tunnel. Huge fans were mounted to suck out the remaining gas and smoke… ‘Methane gas is one of the hazards of mining,’ said Wayne Pryor, a spokesman for Lockheed Shipbuilding and Construction Co. of Seattle, contractor for the project…..

“The tunnel is being constructed for the Metropolitan Water District as part of a multi-billion dollar California Water Project. A Metropolitan Water District spokesman said there were usually 20 men working in the 16-foot diameter tunnel but several always remain above ground.
The blast seriously damaged the extensive ventilation ducts in the shaft, hindering efforts to rid the aqueduct of smoke. Two men who were about a mile from the entrance and a mile from the explosion said the blast knocked their hard hats off.” (Fresno Bee, CA, “Trapped Miners Suffocate Near L.A.,” June 24, 1971.)

Sources

Ferrara, Grace M. The Disaster File: The 1970’s. New York: Facts on File, 1979.

Fresno Bee, CA. “Trapped Miners Suffocate Near L.A.,” June 24, 1971. Transcribed by Stu Beitler for Gendisasters.com. Accessed 2-27-2022 at: http://www.gendisasters.com/california/1346/sylmar%2C-ca-water-aqueduct-explosion%2C-june-1971

National Fire Protection Association. “Multiple-Death Fires, 1971,” Fire Journal, Vol. 66, No. 3, May 1972, pp. 63-65.

National Fire Protection Association. The 1984 Fire Almanac. Quincy, MA: NFPA, 1983.