A fire rattled people living and boating near Orillia's Bridge Port Marina on Saturday.
Orillia Fire Chief Brent Thomas says a boat caught fire after fuelling around 4:40 p.m. The fire set off a series of small explosions.
Staff at the marina turned the fuel pumps off and tried to push the boat to the side.
It isn't clear if anyone was on the boat when the fire started, but no one was injured.
Several local marine units were called in to help extinguish the fire. The Narrows remained closed between Lake Simcoe and Lake Couchiching on Saturday night.