STOCKTON, Calif. --
Five people were injured when a boat burst into flames Sunday afternoon in San Joaquin County.
The blaze happened at Bullfrog Marina around 2:40 p.m. Four women and one man suffered first- and second-degree burns. They were taken to nearby hospitals. Two other people riding in the boat were not hurt.
The San Joaquin County Sheriff's Department is investigating what caused the fire.
Witnesses said the boaters had just finished fueling up. Bystanders said a loud boom came from the boat just seconds after the engine started.
Marina Manager Carl Wenske said he heard people on the boat screaming and saw them jumping into the water to escape.
Sgt. Carey Pehl said fumes likely built up in the engine compartment of the boat and ignited.
"What exactly started it is under investigation," Pehl said.
Marina surveillance video captured the fire as it started. People were seen fleeing, while nearby boaters hurried away.
Meanwhile, other people at the marina jumped into action, grabbing fire extinguishers and a water pump to douse the fire.
Wenske was one of those people.
"It was thick and black, and it was very, very hard to breathe," Wenske said.
Pehl said the fire could have easily been much worse.
"This is an unprotected area of San Joaquin County," Pehl said. No fire department is assigned to the area, and it took sheriff's deputies 15 minutes to arrive.
Pehl credits people at the marina for their quick thinking.
"We're all lucky -- all of us," Wenske said.
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