A fire damaged two boats moored on Lake Union early Friday.
Firefighters were called to the marina at 1800 Westlake Avenue North about 12:25 a.m.
The 36-foot boat was engulfed in flames when firefighters arrived.
Seattle firefighters put out the flames in about 20 minutes. The fire spread to an adjacent boat.
Investigators said they were unable to determine the cause.
Damage was estimated at $270,000.
No one was hurt.