NBC4 footage shows emergency responders on scene where a fireworks mishap led to the injuries of 28 people in Simi Valley.
The operator of a Southern California fireworks show that sprayed the crowd and injured more than three dozen people says a product malfunction appears to be the cause of the "catastrophic failure."
Pyrotechnic operator Bruce Sussin said Monday that they immediately pulled the plug on the July 4 show when the problem occurred at a park in Simi Valley northwest of Los Angeles.
Sussin says fire inspectors checked the site before the show by Bethpage, N.Y.-based Bay Fireworks and everything was fine.
Sussin says he later heard that other operators reported similar problems with some fireworks. He declined to say which ones or who made them.
The American Pyrotechnics Association says there were no immediate reports of widespread problems with a particular firework product over the holiday.