John Hendrickson works across the street from the U-Haul business where the refueling tank is located. He told the Chattanooga Times Free Press the initial blast on Sunday sounded like a cannon. There was a second explosion as firefighters arrived.
East Ridge police on Monday said the explosions were the front tires of the bus exploding.
Cpl. Robert Wade of the police department said the bus was unoccupied and is owned by Quality Drive of Goshen, Ind. It was being taken to a repair facility in Resaca, Ga.
There were no injuries.
The engine section and the front of the passenger compartment were blackened by the blaze.
Information from: Chattanooga Times Free Press, http://www.timesfreepress.com
Copyright 2013 The Associated Press.