(Simi Valley - Bigad Shaban, CBS News)
Investigators are looking for the cause of a fireworks accident that sent more than two dozen people to the hospital.
They now think one of the devices went off early and the blast toppled over other fireworks, which then shot into the crowd.
The 4th of July celebration turned into mayhem when fireworks started exploding on the ground, misfiring into the crowd.
About 10,000 people had settled in to watch the show northwest of Los Angeles.
Two minutes after it started, police believe a wooden platform holding the fireworks gave way.
28 People were injured as flashes of red and white shot across the field.
Spectator Joe Arveeso says it's a miracle he survived. He was watching from the front row. "It'd probably be like a grenade going off right in front of you. Within seconds the fireworks were right in our face."
On Friday, exploded and charred shells were still scattered across the Simi Valley park, along with chairs, tables, coolers, and other items spectators left behind as they ran for safety.
Some of the fireworks never went off and were still here on the field, so police kept people away until all the explosives could be removed.
Captain Mike Lindbery with the Ventura County Fire Department said, "We always insist that the professional shows are the safest, but the dangers are huge. We're dealing with explosive devices. We're dealing with fire and pyrotechnics."
Some of those injured suffered broken bones, and shrapnel wounds but all of the victims are expected to recover.
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