people injured. the most serious, in simi valley, california, fire officials tell us it may have been a chain reaction on the ground that made it so dangerous. >> reporter: for the first two minutes the annual fireworks show in simi valley, california, was some of the fireworks dentally detonated, and according to witnesses they all started guying off at once. some too low to the ground. >> i thought it was pretty spectacular and then everything went crazy and everybody started screaming and everything that was supposed to happen didn't happen. so it was pretty frightening. >> reporter: pieces of fireworks rained down on spectators. >> we had bits and pieces of fireworks coming at us, a big round cylinder block hit the person sitting next to me, not hard, but it did impact her. >> reporter: of the 28 people injured, 20 were taken to the hospital, 16 with minor to