LOS ANGELES (CNS) — Police Chief Michel Moore said Monday human error likely contributed to a destructive fireworks explosion in South Los Angeles, with bomb squad technicians vastly underestimating the amount of explosive material placed into a containment truck.

The June 30 blast occurred as the Los Angeles Police Department attempted to detonate a cache of illegal fireworks deemed too unstable to move. The resulting explosion destroyed an LAPD explosives containment vehicle, damaged multiple homes and injured 17 people.

According to Moore, a preliminary investigation by the Bureau of Alcohol, Tobacco and Firearms and Explosives' National Response Team found that the bomb squad significantly underestimated, based on a visual assessment, the weight of explosive material that was being loaded into the bomb squad truck for detonation.

The truck — which has been used 41 previous times over the last decade, including for three detonations in June — can safely contain the detonation of up to 15 pounds of explosive materials for repeated use or up to 25 pounds for one-time use that would render the truck out-of-service in the future. Bomb technicians followed department protocols to limit handling of the explosive devices and estimated the total amount of explosive material being loaded into the truck was 16.5 pounds, Moore said. The National Response Team's physical weighing of the materials found that the actual amount was 42 pounds.

"We have miscalculations that are significant," said Moore, who publicly apologized to residents for the damaging blast.

Councilman Curren Price, who represents the neighborhood, said in a statement Monday afternoon he was "infuriated" by the findings. He called the error "by far one of the LAPD's largest blunders in recent history, which has further betrayed the trust of our South L.A. community."

"The actions taken by LAPD on June 30 fell short of law enforcement's duty to protect and serve and this act of negligence bears serious consequences not only for the victims, but for our community and the city as a whole," Price said.

"My constituents feel that this was a blatant disregard for their safety and our community of color. This tragedy could have been prevented and I wholeheartedly believe that additional safety precautions would have been taken in a more affluent community. We must take steps to ensure that such a disaster never occurs again in any part of our city!"

Moore insisted during his news conference Monday morning that bomb squad technicians were "operating with the best intentions" in a stressful situation. But he said if mistakes were made in estimating the weight of explosive material placed in the truck, "I will hold the appropriate individuals accountable."

He said the bomb squad has already begun implementing new procedures as a result of the explosion, including the required presence of a commanding officer during future detonations. The department will seek best practices from other departments to evaluate what other changes should be made.

The National Response Team responded to the scene on July 2 and conducted a week-long investigation at the scene. It will formalize a "cause and origin report" based on its field work, 40 interviews with witnesses and personnel, forensic tests and evaluation of damage and surveillance footage. The report will be sent to the National Center for Explosive Training and Research for review, and the LAPD expects to have it in 30 days.

The explosion has heightened tensions among South Los Angeles residents, many of whom are demanding full accountability from the LAPD and accusing the department of showing disregard for the neighborhood by detonating fireworks in the middle of a lower-income residential area. Some have suggested that department members face criminal charges.

During Moore's news conference, one protester began shouting at the chief, hurling expletives and demanding his resignation or firing.

On Monday afternoon, a 27th Street Incident Community Resource Center to assist affected residents opened at the YMCA at 1006 E. 28th St..

The resource center will serve as the designated location where victims can connect with a wide range of services, including opportunities to file a claim, obtain mental health and wellness referrals, as well as other supportive services. The office is open Monday through Friday, 3 p.m. to 6 p.m.

Transitioning from the Local Assistance Center at Trinity Recreation Center, the new site included representatives from Price's office, the city attorney and city clerk, mental health and wellness staff, as well as members of the non-profit All Peoples Community Center who will offer food and clothing.

The blast on East 27th Street sent 17 neighbors and first responders to the hospital, destroyed the LAPD bomb squad truck and damaged 22 residences, 13 businesses and 37 vehicles. Since the explosion, victims who were forced to evacuate their homes have been provided with access to housing, funds needed to satisfy their basic needs like clothing, as well as three meals a day.

"The truth of the matter is the victims of this explosion do not have the luxury of waiting. People are hurting and they need help now," Price said earlier. "At this moment, we are left to pick up the pieces and we need to do whatever we can to help the people that are suffering."

Authorities have said about 32,000 pounds of fireworks were being stored at a home on East 27th Street, where they were being sold. The home's resident, Arturo Ceja III, 27, was charged with illegally transporting tons of explosives. He is set to be arraigned Aug. 2.

Prosecutors said Ceja purchased most of the explosives from a dealer in Pahrump, Nevada. In addition to the commercial fireworks, the initial search of Ceja's residence led to the discovery of more than 140 other homemade fireworks — typically referred to M devices of varying sizes — as well as explosives-making components, including hobby fuses that matched the fuse on a homemade mortar shell wrapped in tin foil discovered inside the residence, according to a court affidavit.

"One thing I don't want to be missed on all of this is that fireworks in general, and homemade pyrotechnic explosives in particular, are the most dangerous items that law enforcement and bomb squad technicians come across when it comes to rendering the items safe," said ATF's Los Angeles Field Division Assistant Special Agent In Charge Michael Hoffman.