SAN BERNARDINO COUNTY, Calif. (KTLA) – Firefighters responded to multiple boats on fire at a lake in California’s San Bernardino County on Friday morning.

After getting a call about smoke and fire at a dock at Lake Arrowhead, crews arrived around 4 a.m. to find boats engulfed in flames that threatened to spread to the dock, according to the San Bernardino County Fire Department.

Crews quickly manned a nearby fire boat, battling the flames from the vessel’s platform.

The blaze burned through several of the boats’ dock lines, leaving them to float freely on the lake while on fire.

Firefighters had to corral the burning boats and extinguish the flames before they could spread elsewhere and wreak more havoc, officials said.

“Boat [and] dock fires pose a hazard for firefighters as both can sink, making the fire boat a vital resource to suppress the fire,” Fire Department officials said in a news release.

It took about 20 minutes to extinguish the flames, according to the Fire Department.

Seven boats were destroyed and another five boats were damaged. The dock also sustained major damage.

Crews spent hours working on overhaul and salvage operations after putting out the flames. A hazardous materials crew also had to respond to the scene to check if any fluids or other hazards might have leaked into the lake.

Images shared by the Fire Department show flames raging from the boats as firefighters use hoses to douse the fire.

In the aftermath, the dock and several boars could be seen badly burned.

Officials said the cause of the fire remains under investigation, and no further details were immediately available.