Note to fireworks staff: it's “the bombs bursting in air.” An accidental detonation of fireworks in Simi Valley ended in shrapnel-like injuries and burns for 28 onlookers gathered to watch the city’s Fourth of July display last night. Witnesses described fireworks shooting sideways into the crowd and a chaotic scene as families ran from the explosions. “There was a big boom. Everybody started running down the street. People were screaming,” said Justice Allen, at the scene. No fatalities were reported.