"I heard a firework go off and we were wondering what was that and then saw thick smoke billowing over our houses," said Joe Bass.
"We took one look at each other," said 16-year-old Joseph Bass, "and decided to run down here because I was hearing screams of fire. So we both ran down this way."
"So I ran over to these houses over here and knocked on their windows and doors and then I hopped their fence," continued Joe Bass, "because I couldn't get in their backyard and grabbed their garden hose and the fence was on fire, so I put out the fence and started spraying down their bushes."
The Contra Costa County Fire Protection District confirms illegal fireworks started the 2-alarm blaze, a fire that damaged one home and threatened at least six others as flames engulfed the wood fencing behind the houses.
A witness told ABC7 News, he saw a group of men at a community park setting off fireworks, and then suddenly the dry field across the street erupted in flames.
"I think they're stupid, especially in California to do that," said Carlos Barron, whose home was spared by a neighbor with a fire extinguisher. "Especially in the summer time. You shouldn't do that."
"It only takes one bottle rocket, one firecracker," said Joe Bass. "It only took one M80 or whatever that was to burn down everybody's fences."