Dozens of Fourth of July celebrants were injured Thursday night in a "fireworks mishap" at a Simi Valley, Calif., park, authorities said.
The injury count changed multiple times over the course of a quickly developing breaking news story. As of 11:30 p.m., 28 people were reported injured, Ventura County Fire Department spokesman Mike Lindbery told reporters at the scene.
Of those 28 victims, 20 were transported to the hospital -- 16 suffered minor injuries, four suffered moderate to severe injuries, Lindbery said. Eight people were treated and released on scene.
Those hurt ranged from young children to the elderly, with injuries that included burns and cuts from flying debris, and some broken bones, Ventura County Fire Department officials told NBC News early Friday. None of the injuries were life threatening.
Between 8,000 and 10,000 people were expected to attend the Independence Day celebration Thursday night. The crowd had been kept at at least 350 feet from the fireworks mortars, the distance required by the fire code, Lindbery told NBC News.
Witnesses said the professional fireworks show lasted just a few minutes before the huge explosion went off.
"We saw about three minutes of the show. There was some that went up in the area and everything just kind of scattered outwards and then everybody just started running," a witness told NBC4.
"Everything exploded and parts came flying everywhere,” another witness told NBC4. “People were running everywhere. So, it was pretty scary."
It happened about 9:20 p.m. at Rancho Santa Susana Community Center and Park (map), said Cmdr. John Parks, a watch commander for the Simi Valley Police Department.
Parks called the detonation a "fireworks mishap." He said initial information suggested the explosion was accidental.
Emergency medical and fire personnel were already at the park to monitor the fireworks show, so the victims were attended to quickly, Parks said.
Initial injury counts reported 20 people were hurt then that figure was revised to 14 before Lindbery detailed 28 hurt in the explosion.
Most of the fireworks were not launched and remained in the mortars, unexploded, he told NBC News.
After the blast, the park was evacuated, Parks said. Aerial footage showed dozens of people lingering on the outskirts of the scene and near the triage area set up on the grass, pictured below.
