A fire that began on a private pleasure boat on Lake Union spread to a commercial vessel and a pier on Friday morning, sending a column of black smoke into the air above Eastlake.

Seattle Fire Department spokesman Lance Garland said there were no injuries but the cause and amount of damage will not be known until investigators are able to board the vessel where the blaze began.

The fire, on the water near East Garfield Street and Fairview Avenue East, was reported about 10:20 a.m. By 11 a.m. the fire was 90 percent contained, Garland said.

However, he said, boat fires can be difficult to suppress because of the separate compartments in each vessel. Additionally, boats can be sunk by too much water, so firefighters are trying to balance suppression with keeping the boat above water, Garland said.

Numerous roads in the area were closed while firefighters worked.