Dozens of spectators were injured in Simi Valley, Calif., Thursday when a malfunction just two minutes into the show sent fireworks flying into the crowd.
Police are still investigating but say it appears the accident happened when a platform holding the fireworks tipped over.
Paramedics took 20 people to the hospital with minor to moderate injuries.
"I thought it was pretty spectacular and then everything just went crazy and everybody started screaming and everything," recalled Joanne Herrera, who witnessed the accident.
"That was (not) supposed to happen so it was pretty frightening," she said. "And a block of wood this big came shooting down and it hit the side of my leg."
"We had bits and pieces coming down on us. A big round cylinder block hit the person next to me," another witness, Gregory Perkins, said.
Immediately after the incident, authorities stopped the show and evacuated the field. A bomb squad de-activated the remaining fireworks.
Nationally, fireworks safety is a big concern, with trauma professionals treating 10,000 people a year for fireworks-related injuries.
Ironically, their advice is to go to professional displays rather than risk setting off explosives at home.