On Aug. 17, 1907, a fire at the Prest-O-Lite factory at 229 E. South St. downtown led tanks of acetylene gas to explode, sending pieces of steel flying through the air. Firemen had to stay back during the explosions but eventually were able to prevent more catastrophic damage by keeping a steady stream of water on tanks holding calcium carbide, which could have caused larger problems. The factory used the acetylene gas to produce headlamps for vehicles. The company would continue work in the damaged building, but additional explosions occurred in December 1907 and June 1908, just after the city council voted to force Prest-O-Lite to move its operations outside city limits
The photo is courtesy of the Indiana Historical Society and is part of the W.H. Bass Photo Company collection. More images are available at images.indianahistory.org.
Sources: “James Allison: A Biography of the Engine Manufacturer and Indianapolis 500 Cofounder” by Sigur E. Whitaker; Indiana Historical Society, FirstSuperSpeedway.com