Fireworks may have started fast-moving fire near homes in rural Martinez near Highway 4

MARTINEZ, Calif. (KGO) -- In the East Bay, it was a long afternoon for fire crews who were looking to get a handle on a fast-moving grass fire which burned near Highway 4 in Martinez. Authorities say it was possibly sparked by illegal fireworks, and it wasn't the only fire started that way.

"I've got to the point where I can tell how close the fire is, and it was very close," said Homeowner Marjorie Moore.

RELATED: SJ resident climbs roof to stop fire ignited by Illegal fireworks

Sky7 was over the firefight which looked like a smoky battlefield. The fast-moving grassfire racing up a hill near Franklin Canyon Road, close to Highway 4 in Martinez. CalFire helicopters and air tankers dropped water and retardant. It grew to 24 acres, threatening Moore's ranch for about an hour until it was contained.

EMBED More News Videos

Crews are battling a fast-moving brush fire in a rural area of Martinez off Wolcott Lane, between Highway 4 and Franklin Canyon Road. Here's a look overhead from SKY7.

"I brought my car up the driveway so I could evacuate, wondering why I didn't put a container together with everything I needed," said Moore.

"It was certainly started by a human," said Steve Hill with Contra Costa County Fire Protection District.

Fire officials now have an idea of how the fire started.

"It was caused by something hot, not a cigarette butt, but possibly fireworks," said Hill.

Firefighters got a workout on the 4th of July all over Contra Costa County. There were so many grass fires, they almost lost count.

"37 fires in 6 hours last night, we believe every one of them started by fireworks," said Hill.

No one was hurt and no structures were lost.

Copyright © 2019 KGO-TV. All Rights Reserved.