The Rancho Santa Susana Community Park remained closed Friday as authorities began their investigation into the accident. Both the police and fire departments are investigating. They said it could take several days to figure out what happened.
Bay Fireworks, the company hired to handle the show, said in a statement that it "deeply regrets that people were injured during the Simi Valley fireworks display."
The company stressed that workers are trained on a regular basis, and their equipment had been inspected and approved by authorities.
"Bay Fireworks will conduct a thorough and complete investigation of this incident and make our findings available to the public," the company said.
Cmdr. Stephanie Shannon with Simi Valley police said at this point, there are no indications of foul play.
"This appears to be completely an industrial accident and that is why Cal/OSHA has been notified. We will continue with our investigation and we will try to determine to our best ability exactly what's happened," said Shannon.
At a Friday morning news conference, fire and police officials did not reveal many details on their investigation, only saying the efforts of the emergency personnel on site during the incident helped mitigate civilian injuries.
Pieces of black debris and chunks of wood were seen strewn across the park's soccer field. While dozens of people were hurt, none of the injuries were life-threatening. Children and elderly individuals were among those injured.
It quickly became clear Thursday night that something was awry when the explosions were going off low in the air and on the ground. That's when the shrapnel from the fireworks flew directly into the crowd.
"When I heard it, I knew something was wrong. I mean, it sounded like a bomb to me. It was really loud because I guess it all went off at once," said Diane Minor, a Simi Valley resident.
The blasts shattered windows at homes across the street. Also, there was a gaping hole in a fence, made when some sort of wooden box flew through the air with enough force to go right through.
It was supposed to be a fireworks extravaganza, but it quickly became a danger zone for the families seated with a clear view.
Paulina Mulkern, 21, grabbed her two young cousins and tried to shield them from flying debris and sparks.
"I just see a firework close to us and it just popped really close and I did feel two of them hit my back. My hair got burnt," said Mulkern.
Mulkern says her sweater was singed and when the explosions stopped, she experienced her first-ever panic attack.
"Off-duty nurses, two of them, were trying to calm me down," said Mulken.
She was one of 20 patients taken by ambulance to area hospitals. The victims were transported to Simi Valley Hospital, Los Robles Hospital and Medical Center and Providence Holy Cross Medical Center. Many of the victims suffered just minor injuries, but four individuals suffered serious injuries. Los Robles said it treated eight patients, who have since been released. Holy Cross treated two people, who have also been released.
Simi Valley Hospital President Kim Milstien said her hospital treated 26 patients ranging in age from 17 months to 71 years old. Of those patients, she said 23 were released. Milstien said the two remaining patients are a 21-year-old man, who was admitted for leg trampling injuries, and a 55-year-old man, who was admitted for chest pain. They were both listed in fair condition.
Milstien also said a 17-year-old female was transferred to Grossman Burn Center. Her condition was not known. A Grossman spokesman said a total of five patients were evaluated and treated at their facility following the incident.
Overall, Milstien said the injuries included burns, trampling, shrapnel and chest pain. Twelve of the victims at Simi Valley Hospital were under 18 years old.
Police and firefighters were already on scene at the time of the incident because they were stationed at the park as part of the event's safety protocol. Emergency officials were administering aid, in some cases, while the explosions were still going off.
After the explosions, bomb squad officials were called in because some of the fireworks had not detonated. Authorities and pyrotechnics specialists rendered those fireworks safe.