1947 — Feb 20, Chemical Explosion, O’Connor Electroplating Works, Los Angeles — 17
Compiled by Wayne Blanchard 10-15-2023 for upload to: https://www.usdeadlyevents.com/
–15-17 AP. “Blast’s Violence Like Nitroglycerin.” The Bakersfield Californian, 2-22-1947, p. 1.[1]
— 17 NFPA. “Fires Causing Large Loss of Life.” Handbook of Fire Protection. 1954, p. 35.
— 17 NFPA. “Large Loss Fires of 1947.” Quarterly, Vol. 41, No. 3, Jan 1948, p. 175.
— 17 National Fire Protection Assoc. “Recent Fires.” Quarterly, V40, N4, Apr 1947, p. 275.
— 17 UP. “Los Angeles Blast Inquest March 11.” Oxnard Press-Courier, CA, 2-24-1947, p.3.
— 15 Connellsville Daily Courier, PA. “Blast Like That of A-Bomb…,” February 21, 1947.
— 15 Cornell, James. The Great International Disaster Book (Third Edition). 1982, p. 285.
Narrative Information
National Fire Protection Association, Apr 1947: “Feb. 20, 1947, Los Angeles, Calif. Perchloric Acid Explosion.
“Seventeen persons were killed and more than 130 injured when a shattering explosion demolished the one-story brick-joisted plant of the O’Connor Electro-Plating Corp. and either wrecked or damaged 28 neighboring buildings, including 24 dwellings, 3 one-story brick mercantile buildings and a frame church. Interior partitions were damaged and windows broken in structures within an area of 12 city blocks. Fire that broke forth in the building of origin did some additional damage. Rapid work by gas company employees prevented ignition of escaping gas in other affected properties.
“At the time of the explosion the plant was engaged in a new method of electrolytic polishing of aluminum which removed the outer film of metal electrically, leaving the surface bright. The process involved the use of an electrolyte consisting of 300 gals. Of perchloric acid-acetic anhydride solution. This mixture was placed in a steel, plastic-lined vat, 6 ft. long, 2½ ft. wide and 3½ ft. deep, in which the aluminum was suspended in a metal basket during treatment. The tank contained a plastic screen to catch any parts that might fall from the basket. On the previous day a plastic rod had been introduced to hold the screen near the bottom. According to statements of survivors aluminum fountain pen caps, after machine work under oil, were cleaned, placed in a basket (which acted as the cathode) and lowered into the perchloric acid solution.
“The process was installed and operated under the supervision of an alleged chemist, who, it was subsequently determined, had not had the technical training and university degrees when he claimed. The process had been in use for 4 days when, about 9:45 a.m. on Feb. 20, the vat started to heat violently. A refrigeration system, designed to prevent hearing, was not in operation at the time.
“The ‘chemist’ and a helper were approaching the vat when it exploded, presumably due to the disintegration of perchloric acid which, in addition to being a powerful oxidizing agent, is subject to explosive decomposition when heated. The explosion effect was said to be similar to what might have been expected from the explosion of 1½ tons of nitroglycerine. The blast left a hole 8 ft. deep and 20 ft. in diameter beneath the spot where the vat had stood on a 4-in. earth-supported concrete floor. Disintegration was so complete that no identifiable part of the vat or of the bodies of the ‘chemist’ and his helper could be found.
“It is know that organic material will react violently under certain conditions with perchloric acid. The most plausible theory, as indicated by expert testimony at the coroner’s inquest, was that the acid solution became contaminated by organic material, probably the recently installed plastic rod. An exothermic reaction took place, which heated the perchloric acid to the point of explosion. Loss: $2,000,000.” (National Fire Protection Association. “Recent Fires.” Quarterly, Vol. 40, No. 4, Apr 1947, pp. 276-277.)
National Fire Protection Association, Jan 1948: “Feb. 20, Los Angeles, Calif. A perchloric acid explosion in an electroplating plant caused the damage illustrated [photo omitted here] and additional damage to other structures in a twelve city block area. Seventeen persons were killed and property damage and public liability losses are presently estimated at $3,500,000. The process involved the use of an electrolyte consisting of 300 gallons of perchloric acid-acetic anhydride solution. This mixture was placed in a steel, plastic lined vat 6 ft. long, 2½ ft. wide and 3½ ft. deep in which aluminum was suspended in a metal basket during treatment. The acid solution probably became contaminated by organic material and an exothermic reaction took place which, under the influence of evolved heat, resulted in the explosion.” (NFPA. “Large Loss Fires of 1947.” Quarterly of the National Fire Protection Association, V.41, N.3, Jan 1948, pp. 153-195, p. 175.)
Newspapers
Feb 20: “Los Angeles, Feb. 20 — An explosion today demolished a downtown plating works, shattered buildings throughout the block, and injured many persons. At least 10 persons were killed, and more than 100 injured. Fire Chief John Alderson said it was the city’s worst explosion.
“A solidly-built six-story building across the street absorbed most of the concussion, he said, preventing the blast from leveling the entire block. Alderson said some of the bodies were burned so badly it was impossible to determine sex. ‘The people inside were almost cooked alive by the terrible heat,’ he said. Cries could be heard from persons trapped in the wreckage.
The entire one-story brick building housing the O’Connor Plating Works at Pico and Stafford streets collapsed in the explosion at 9:45 A. M. (PST). Windows two miles away were broken. The explosion was heard 15 miles away…” (Connellsville Daily Courier, PA. “Los Angeles’ Worst Blast Causes 10 Deaths; Bodies Burned Beyond Recognition.” February 20, 1947.)
Feb 21: “Los Angeles, Feb. 21 — Bulldozers and steam-shovels ground through the debris of an electroplating plant today, clearing the way for an investigation of the explosion which leveled a city block and left 15 persons dead and hundreds injured. The death toll was established by Coroner Ben Brown, who said that the casualty figure may be revised upward from the list of critically injured. More than 100 of the known 200 injured remained in hospitals today.
”The city’s worst explosion might have been caused by a breakdown in the plant refrigeration system only an hour earlier, Fire Prevention Chief Earl H. Richardson, said. He said the plant was using a new plating process for aluminum which employs concentrated perchloric acid. The acid is so volatile it must be kept under constant refrigeration.
”The mushrooming blast, so deafening that persons miles from the scene believed an atom bomb had fallen, left an estimated 500 survivors homeless. At least 100 families were fed in emergency canteens and then transferred to housing projects for the night. Many of them lost all their possessions when the explosion tore up their homes.
”Property damage amounted to $1,000,000 and possibly may double that. The one-story O’Connor electro-plating works was virtually disintegrated. A dozen homes in the same block were demolished. Thirty others were said by city building inspectors to be unsafe until repaired. A total of 300 buildings were demolished or damaged. Windows were broken two miles away.
“A 12-year-old…boy riding his bicycle three blocks distant was killed by a flying pipe. The reverberating roar and blast shook homes more than 15 miles from the scene….
”John J. O’Connor, the 68-year-old owner, said the blast might have been from a short circuit in a vat of chemicals. He was near collapse as he looked over the wreckage. Fire Chief John H. Alderson said it was “only a miracle” that more were not killed. Twenty-six persons were in the plant at the time, although at other times 70 are employed. The blast broke gas mains and felled power lines. Occupants of all buildings within two blocks of the industrial area were evacuated in fear of fire.” (Connellsville Daily Courier, PA. “Blast Like That of A-Bomb,” Feb. 21, 1947.)
Feb 22, AP: “Los Angeles, Feb. 22. (AP) – Chemical experts agreed today that a 300-gallon mixture of chemicals equivalent of 3600 pounds of explosive virtually as violent as nitroglycerin caused the downtown Los Angeles explosion which killed 15 and injured 158 Thursday. A mixture of perchloric acid and acetic anhydride was the lethal potion which disintegrated the O’Connor Electro-Plating plant, wrecked nearly a block of buildings and rattled a square mile of the city, said Police Chemist Ray Pinker, Captain Carl Halter of the fire department arson squad and G. I. Cheney, analytical chemist. Workmen still searched today for two persons still missing. The three said the blast…caused damage in the area estimated at $1,500,000 by fire officials.
“Captain Halter said the mixture of the two chemicals was first used at the plant last September to put a high shine on aluminum articles. He said the process apparently was devised by Dr. Robert M. Magee, 35, a graduate of California Institute of Technology.
“Although an intensive search continued today through the twisted wreckage, no trace had been found of Doctor Magee and his assistant, Alice Shemeta Iba, 21-year-old Japanese-American girl who was hired just last Saturday. Doctor Magee and the assistant were in his office at the time of the explosion. The three experts said they believed these to had been blown to bits and that the search for their bodies probably is hopeless….” (AP. “Blast’s Violence Like Nitroglycerin.” The Bakersfield Californian, 2-22-1947, p. 1.)
Feb 22, INS: “Los Angeles, Feb 22. (INS). Evidence indicating that one of the victims of Thursday’s disastrous explosion was the chemist whose secret formula has been blamed for the blast was found today amid the ruins of O’Connor Electro-Plating factory. The chemist, Dr. Robert Magee, nephew of M. C. Schafer of Long Beach, who was injured in the blast, has been missing since the explosion, along with his assistant, Alice Shemeta Iba, 21-year-old Japanese-American girl. Today, on the edge of a 15-foot crater in the center of the demolished building, investigators picked up what appeared to be fragments of human bones and a piece of a man’s coat. Both the bone fragments and the cloth are being subjected to laboratory analysis.
“Fire department officials theorized that Dr. Magee and Miss Iba were standing beside a vat, mixing his formula, when, for some reason, the mixture exploded. Capt. Carl Halter of the fire department arson squad said he had learned that the formula involved the use of perchloric acid and acetic anhydride. It was employed in a new process for electro-plating aluminum. Halter said: ‘Magee was well aware of the explosive nature of the solution. He had been using it since last September and was in the final phases of perfecting the process before requesting a patent.’
“The disaster claimed a known 15 lives, seriously injured 158 persons and wrecked nearby buildings, rendering 185 families homeless.” (Independent News Service. “Scientist Believed Killed in Blast.” Long Beach Independent, CA. 2-23-1947, pp. 1 and 40.)
Feb 25, UP: “Los Angeles (U.P. – An inquest into a plating works explosion that killed a possible 17 and injured 134 persons, the most exhaustive study of devastation ever conducted here, was set today for March 11.” (United Press. “Los Angeles Blast Inquest March 11.” Oxnard Press-Courier, CA, 2-24-1947, p. 3.)
Sources
Associated Press. “Blast’s Violence Like Nitroglycerin.” The Bakersfield Californian, 2-22-1947, p. 1. Accessed 5-18-2020: https://newspaperarchive.com/bakersfield-californian-feb-22-1947-p-1/
Connellsville Daily Courier, PA. “Blast Like That of A-Bomb Levels Los Angeles Area.” 2-21- 1947. Accessed 5-18-2020 at: http://www.newspaperarchive.com/PdfViewerTags.aspx?img=32785525&firstvisit=true&src=search¤tResult=1
Connellsville Daily Courier, PA. “Los Angeles’ Worst Blast Causes 10 Deaths; Bodies Burned Beyond Recognition.” February 20, 1947. Accessed 5-18-2020 at: https://newspaperarchive.com/connellsville-daily-courier-feb-20-1947-p-1/
Cornell, James. The Great International Disaster Book (Third Edition). New York: Charles Scribner’s Sons, 1982.
Independent News Service. “Scientist Believed Killed in Blast.” Long Beach Independent, CA. 2-23-1947, pp. 1 and 40. Accessed 5-18-2020 at: https://newspaperarchive.com/long-beach-independent-feb-23-1947-p-1/
National Fire Protection Association. “Fires Causing Large Loss of Life.” Handbook of Fire Protection (11th Ed.). Boston, MA: NFPA, 1954, pp. 33-36.
National Fire Protection Association. “Large Loss Fires of 1947.” Quarterly of the National Fire Protection Association, Vol. 41, No. 3, Jan 1948, pp. 153-195.
National Fire Protection Association. “Recent Fires.” Quarterly, Vol. 40, No. 4, Apr 1947, pp. 265-280.
United Press. “Los Angeles Blast Inquest March 11.” Oxnard Press-Courier, CA, 2-24-1947, p. 3. Accessed 5-18-2020 at: https://newspaperarchive.com/oxnard-press-courier-feb-25-1947-p-3/
[1] Fifteen bodies recovered; two others in nearby office missing and believed by investigators to be “blown to bits.”