Kids dig hole and build out-of-control fire that caused 'mushroom cloud' in Martinez

An inferno that destroyed a Martinez home on Wednesday was caused by juveniles playing with fire: Investigators say it all started with three youngsters who dug a hole and built a fire in it, but it got away from them.

The 2 p.m. fire caused an explosion in high-power lines and an outage affecting about 8,000 customers.

"It was traumatic, it blew one, two, three, four times," said Vine Hill resident Edward Raya, who described propane tanks exploding.

His neighbor, whose property burned, is an auto mechanic and car collector who stored numerous vehicles, motorcycles and combustible materials.

They were all charred.

SEE ALSO: 3 youths blamed for starting fire that engulfed Martinez home, neighbors startled by fireball

"When it blew and made a mushroom cloud, it blew everything at once, and his house it burned to the ground," said Raya.

About a dozen homes in the vicinity were threatened, but saved due to an aggressive firefighting response, as the fire immediately went to two alarms.

The nearest neighbors lost a shed and fences

Considering how sudden, and how close, the fire was, they were lucky.

Access to the streets involved is narrow, with one way in and out.

Fortunately, winds had not intensified at that time of day.

"We definitely dodged a bullet," said Contra Costa Fire's Steve Hill.

"It wasn't quite as windy in the early afternoon as the late afternoon, so the Incident Commander didn't think wind was a factor."

But dry grass was a factor.

On a hill below the property, three boys had been seen playing.

Investigators say they dug a hole and lit a fire in it, but it took off in the grass.

"The fire traveled up the hill and there was no way to stop it, the kids tried, they tried, " said witness June Christie, who called 911.

Living next to the hill, she said the dry conditions were already a concern.  

"We've been a lot worried with this field behind us and the grass hadn't been cut down yet so it's cut down now," said Christie ruefully.

The fireball, so huge and scary for the neighborhood, was caused by the smoke's contact with high-tension power lines running above the fire.

"That smoke went straight up into those power lines," explained Battalion Chief Vito Impastato, Incident Commander.

"At one point it just conducted the energy there and that's when the explosion happened." 

By that time, there was no saving the house, and the owner, watching the mop-up, declined to comment.

"There isn't anything you can say and I don't know if it's sunk in yet for him, it all happened so fast," said neighbor Pamela Smith.

The three youngsters who accidentally started the fire were questioned as part of the investigation and released to their parents.