Balloon in car creates XL explosion Tuesday, February 7, 2006; Posted: 8:40 a.m. EST (13:40 GMT) SHERIDAN, Colorado (AP) -- A couple planning to set off their own Super Bowl pyrotechnics accidentally blew up their own car while transporting a balloon filled with an explosive gas. Norman Frey, 46, and his companion suffered busted eardrums in the explosion Sunday as they drove to a party for Super Bowl XL, according to the Arapahoe County sheriff. The balloon had been filled with acetylene, a flammable gas used in welding, and it had rolled across the back seat, possibly causing static electricity that ignited the gas. The explosion broke windows, bent doors outwards and pushed up the roof about a foot. "Looking at the car closely, it's amazing that these people weren't killed," Sheriff Grayson Robinson said. Several people reported the explosion, but when a deputy arrived, Frey and the woman had abandoned the vehicle. The license plate led them to Frey, who faces a felony charge of possession, use, or removal of explosives or incendiary devices. The woman will not be charged, authorities said.