LOS ANGELES (CNS) — Los Angeles Police Department and federal ATF investigators were combining efforts Thursday to determine what caused a huge explosion that injured 17 people, including 10 law-enforcement officers, after police attempted to safely detonate illegal fireworks that were seized at a house in South Los Angeles.

"Throughout the night, we did a sweep of the surrounding blocks to make sure there were no devices that were hazardous to the community members here," LAPD Lt. Raul Jovel told a local news station.

Some of the injured reportedly were people who didn't answer the door when officers attempted to evacuate the area prior to the ill-fated blast.

What You Need To Know

  • A cache of illegal fireworks seized at a South LA home exploded Wednesday evening, damaging nearby homes and cars and injuring multiple people

  • Police had called in a bomb squad after a tip led them to seize some 5,000 pounds of illegal pyrotechnics at about noon

  • One man was arrested on suspicion of possessing fireworks and destructive devices and also on suspicion of child endangerment because two children were found at the home, police said

  • Some of the fireworks appeared to be large mortar-sized devices used for commercial purposes

"There's certain limits as to us going into homes in different situations," Jovel said. "In that situation, whoever was in charge felt that it was safe to detonate it. They followed the procedures in place."

The evacuation area was reduced to Adams Boulevard to 28th Street and from San Pedro Street to Stanford Avenue, according to an LAPD update. People who live within the impacted area and need to retrieve medicine, medical equipment, ID or pets were told to go to 28th and San Pedro streets to arrange access.

A total of 17 people were injured in the blast, ranging in age from 42 to 85 years old. One declined transport to a hospital. An 85-year-old woman, 60-year-old man and 51-year-old woman suffered moderate injuries, according to the Los Angeles Fire Department's Margaret Stewart. The remaining patients, including the 10 law enforcement officers, suffered minor injuries. Most of the injured were released overnight, according to reports from the scene.

Meanwhile, a man was in custody Thursday morning in connection with the fireworks. Arturo Cejas III, 27, was arrested on suspicion of reckless or malicious possession of a destructive device. He was being held on $500,000 bail, LAPD Officer Tony Im said.

Around 6:40 p.m. Wednesday, police attempted to dispose of some of the approximately 5,000 pounds of fireworks they discovered earlier in the day by detonating them in an armored container in the 700 block of East 27th Street, near San Pedro Street, LAPD Chief Michel Moore said at a late-night news conference Wednesday.

However, the force of the blast destroyed the container — and damaged nearby homes, shattered glass in the neighborhood and caused damage to several cars parked on the street.

A local news outlet reported Thursday morning that at least a dozen homes were damaged, and that the damage extended at least half a block from the blast.

"Clearly, protocols were followed and pursued, but something happened in that containment vehicle that should have not happened and we don't know why," Moore said. "We intend to find out why."

"I'm thankful and grateful (the injuries) are non-life-threatening," Moore said.

Mayor Eric Garcetti tweeted that he has directed the LAPD "to conduct a full investigation into this incident, so we can better understand why this happened."

LAPD officers and the Crisis Response Team continued to survey the neighborhood for more injuries and make sure the area was safe, according to Garcetti.

Kenneth Mejia, a candidate for city controller in the 2022 election, called for "an independent auditor to conduct the investigation on why this happened."

"As city controller, we'd do that and work with experts to get down to what happened and how much money this will cost our city," Mejia tweeted. "There needs to be accountability."

Moore said the fireworks were brought from out of state "for resale to members of the community."

He said police also found 40 "Coke-can sized" devices with fuses attached and 200 smaller devices.

"Those devices are even more unstable than the fireworks," Moore said.

Several homes were damaged by the explosion, and Los Angeles Department of Building and Safety personnel were evaluating them to determine if anyone will need emergency shelter.

City Councilman Curren Price issued a statement saying his staff is set up with the American Red Cross at Trinity Park, 2415 Trinity St., to provide affected residents with food, clothing and other needed services.

"One of the main questions that myself and my constituents want to know is why this happened in a densely populated residential area?" Price asked.

Los Angeles Fire Department Chief Ralph Terrazas said those who want to see fireworks on the Fourth of July should go to a fireworks show and not use purchased fireworks, which are illegal in Los Angeles.

"Every year, we see the devastation and the destruction that they cause. Fireworks are no joke," he said.