Fire Department Spokesman Brian Alkins said the 24-foot vessel started to drift off its mooring, and the 75-foot cruise ship "Odyssey" was evacuated, because fire officials were afraid the burning boat would hit it.
Fire officials were able to pull the boat back before it could hit the larger ship. The inside of the boat was completely burned out.
They towed the burned-out boat to a dock on the shore, where it eventually sank, Alkins said.
The Fire Department deployed booms around the sunken boat so fuel wouldn't leak out into Boston Harbor.
No one was on the boat at the time, and no one was injured.
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