Overloading of a containment vessel used by the LAPD bomb squad to destroy illegal fireworks was the cause of a late June explosion that rattled a South Los Angeles neighborhood and left 17 people injured, according to a federal report.
The Bureau of Alcohol, Tobacco and Firearms report released Tuesday found the chamber designed to contain the powerful detonation was inadvertently overloaded with explosives found days before the Fourth of July in a home in the 700 block of East 27th Street. The resulting explosion shattered windows and cast debris throughout the neighborhood, displacing some residents.
Los Angeles Police Chief Michel Moore earlier said that human error likely contributed to a the explosion, with bomb squad technicians vastly underestimating the amount of explosive material placed into a containment truck.
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The man who stockpiled the illegal fireworks now faces a decade in federal prison. Arturo Ceja III, 26, pleaded guilty to one count of transportation of explosives without a license.
The explosion also prompted the Los Angeles Police Department to review its detonation procedures. Five bomb techs have been taken off their field duties and could face discipline.
In a statement, the LAPD said it identified 13 specific actions being taken in response to the destructive detonation to prevent it from happening again.
"A number of the actions identified have already been implemented including the prohibition of the use of the Total Containment Vessel for the onsite disposal of explosives in a residential setting," the statement continued.
Ceja admitted to making several trips to Nevada in late June to buy fireworks — including homemade ones that were made out of cardboard and packed with explosive flash powder, federal prosecutors said. Fireworks can be sold in California for up to four times the purchase price in Nevada, officials said.
Police discovered about 32,000 pounds (16 tons) of commercial-grade fireworks on Ceja's property on June 30 after following up on a tip. Law enforcement also found 140 homemade fireworks and explosives-making components.
Fireworks are illegal to sell or possess in Los Angeles and in unincorporated areas of the county.
The bomb squad decided to detonate the homemade in the neighborhood — believing they were too unstable to transport elsewhere. They examined them by X-ray and robotics and loaded them into the detonation chamber, officially called a total containment vessel, without weighing them with a scale.
The technicians grossly miscalculated how much explosive material they were loading into the chamber and the entire vessel exploded.
Residents in the neighborhood have called for accountability and asked why some people were still in their homes, despite a door-to-door evacuation order. Some victims have filed legal claims — the precursor to a lawsuit — against the city.
