Firework malfunction responsible for July 4th disaster in Simi Valley

Simi Valley police investigate the scene where fireworks exploded and shot into the crowd during a Fourth of July celebration.
(Irfan Khan / Los Angeles Times)
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A malfunctioning firework caused a dramatic Fourth of July pyrotechnic disaster in Simi Valley that injured dozens of people, fire officials concluded in a report released Thursday.

A 5-inch-wide firework shell failed to leave its mortar tube and exploded inside, sparking a chain reaction that knocked down the display and sent debris and firework projectiles flying toward about 10,000 spectators watching hundreds of feet away.

The incident was investigated by Cal/OSHA, CalFire and the Ventura County Fire Department.

“All of the information we have on this incident indicates that there was simply a tragic malfunction that resulted in the explosions,” said Ventura County Fire Chief Mark Lorenzen. “As a result, we will be reviewing the state fireworks policies to see if additional local measures might be warranted.”


Video footage showed fireworks exploding at ground level and into the crowd as people screamed and ran for cover. Police said after the initial chaos, the crowd left in an orderly manner.

“There was a big boom. Everybody started running down the street. People were screaming,” Justice Allen, 17, of Simi Valley told The Times after the incident. “Everybody was just terrified. People hid in bushes.”

Twenty-eight people were injured, with the victims ranging in age from 8 to 78. Twenty people were taken to local hospitals with non-life-threatening injuries. Most were described as shrapnel-like injuries or burns.