A controlled detonation of Illegal fireworks and homemade explosives injured 10 LAPD officers, an ATF agent and six other people Wednesday night when the bomb squad's disposal vessel experienced some kind of catastrophic failure.

One officer remained hospitalized Thursday, KTLA reports.

According to the Los Angeles Fire Department, the worst of the injuries were among civilians, who were a 60-year-old man, 85-year-old woman and 51-year-old woman with moderate injuries. The rest of the injured suffered minor injuries.

The blast came around 7:30 p.m. Wednesday outside of a home where police had spent the day seizing a large cache of fireworks. They also came across about 40 homemade “coke can-sized” devices with powder and fuses on them, and 200 smaller similar devices. The bomb squad determined them to be “very volatile.”

“That’s why it was decided to really blow that stuff up here in place, in a controlled manner,” LAPD Lt. Raul Jovel said Thursday during a news briefing. The crew loaded what is believed to be less than ten pounds of the destructive material onto a commercial grade semi-truck with an iron chamber with a venting system.

“During that controlled detonation, we had catastrophic failure of one of our trucks,” he added.

“Something happened in that containment vehicle that should not have happened. And we don’t know why, but we intend to find out why,” LAPD Chief Michel Moore said at a news conference following the blast.

The officers were called to the home around 8:40 a.m. that day after someone reported that there were fireworks being kept at the home.

They walked into the house to find about 5,000 pounds of fireworks stacked in boxes, totaling eight to 10 feet high in the back of the house and patio, according to the Police Department.

Arturo Cejas, a 27-year-old man in the home, was taken into custody, and he faces charges related to possession of a destructive device, LAPD said. He may also face additional charges because there was a 10-year-old in the home where the fireworks were being kept.