On Thursday night, a collection of fireworks detonated early at a July 4th celebration in Simi Valley, launching them into the crowd of spectators, according to the LA Times. The incident at Rancho Santa Susana Community Park injured 28 of the roughly 10,000 people in attendance.

Cameron Wapner‘s shocking footage of the explosion shows the fireworks detonating at ground level, causing chaos and panic among the crowd.

[via Muck Rack]