It appears a furnace is to blame for the massive fire in Marmora Tuesday morning.
Around 8 a.m., emergency crews were called to Ted Bonter Marine of Highway 7, where the building and its contents were completely destroyed.
Fire Chief Tony Brownson says the damage estimate is between $3 and $5 million.
He says the building was full of vehicles.
He says the fire began in an oil furnace.
One employee was at the shop at the time, but was outside when the flames began.
They are fully insured.