Shannon said most people responded admirably and left in an orderly fashion. A bomb squad was sent to the park to deactivate the remainder of the fireworks.
Shannon said the fireworks primarily shot in one direction.
"They are going to travel the same distance across the park as they would in the air," she said. "The ones that had actually ignited that had to run their fuse were going directly into the crowd."
Simi Valley, home to the Ronald Reagan Presidential Library, is about 40 miles northwest of Los Angeles.
Other fireworks mishaps in the U.S. Thursday:
— A 32-year-old working at a fireworks show in Ojai, Calif., was struck by fireworks that apparently exploded on the ground, according to Erika Monterroza, spokeswoman for the California Division of Occupational Safety and Health. The worker's face and left leg and arm were injured. The worker was taken to a local hospital and transferred to a burn center.
— One person was killed and others injured after a pickup plowed into pedestrians after the fireworks show in Grand Lake, Colo. The 33-year-old driver was arrested and is being held on suspicion of driving under the influence as investigators piece together what happened. Colorado State Trooper Josh Lewis says initial reports indicated those hit were on the side of the road.
— A barge being used to set off the annual Fourth of July fireworks on Whitefish Lake in Montana caught fire just as the grand finale began. The local fire chief said a spark from a low-bursting firework started the blaze. The two pyrotechnicians on board dove into the water. No one was injured.
— A worker at a fireworks show in North Myrtle Beach, S.C., was injured when a shell exploded prematurely. The explosion at the Cherry Grove Pier caused the show to end early, after just six minutes, and left a hole in the pier.
— In Seattle, fire investigators blamed illegal fireworks for a blaze that damaged 14 boats at a storage facility as the city's official fireworks display was exploding nearby, causing an estimated $1.5 million in damages. One firefighter received minor injuries fighting the fire.
— A pyrotechnician suffered severe head trauma and burns after fireworks malfunctioned during a display in northwestern Arizona.
— A barge being used to set off fireworks on Whitefish Lake in Montana caught fire just as the grand finale began. The two pyrotechnicians on board dove into the water, and no one was injured.
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