More than a dozen Fourth of July celebrants were injured Thursday night in a "fireworks mishap," according to Simi Valley police.

The incident 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.

The injury count was revised from 20 to 14 victims Thurday night, according to a dispatch officer with the Ventura County Fire Department.

Citing early information, Parks said earlier in the night that 20 people were hurt.

Hed called the detonation a "fireworks mishap.