Authorities were trying to determine the cause of a fire that started on a dry-docked boat Thursday at Bartlett Lake in Arizona.

The fire touched off a blaze that burned at least five other boats, authorities told azcentral.com. 

The amount of damage was unclear: A spokesman from the Maricopa County Sheriff’s Office said two to three boats were destroyed; a Rural Metro fire spokesman said one was destroyed and five others were damaged.

Fire crews responded after the sheriff’s office received a call before 6 a.m. about a fire at the marina, officials said.

Bartlett Lake is in the Tonto National Forest about 45 miles northeast of Scottsdale.

Officer Chris Hegstrom, a sheriff’s spokesman, said two to three boats were destroyed, along with the marina.

Smoke still emanated from the charred boat about 7 a.m., but helicopter footage showed that the fire was mostly out. The boat was parked among others in a lot near the lake.