Emergency crews responded midday Thursday to a fire at the home in Simi Valley, located in Ventura County in the greater Los Angeles area.

First responders from area fire departments declared a mass casualty incident for the protestors who were injured in Ventura County

California has seen a spate of accidental fireworks explosions leading up to the Fourth of July with a Thursday morning detonation killing 1 in a Simi Valley home and a similar incident critically injuring two people in a Bay Area residence.

Seven people were "unaccounted for" in Yolo County's town of Esparto after several explosions at a fireworks warehouse resulted in a fire, officials said.

Human remains have been found at the warehouse filled with fireworks that exploded in Northern California this week, officials said.

Roseville firefighters battled a fire around midnight Sunday on Oakmont Drive near South Cirby Way and Old Auburn Road.

One person is dead after a house fire in Simi Valley, which authorities determined to be caused by explosions from fireworks on Thursday afternoon.

A volunteer Esparto firefighter is on leave amid reports he worked for the fireworks companies on property owned by a sheriff's deputy.