Wow awesome explosion on Menards RR.
Wonder how many PSI the tire got to before exploding?
UPDATE: Team owner Richard Childress said Monday that his team was still uncertain what caused a pit-road explosion that blasted the #27 Chevy driven by Team owner Richard Childress said Monday that his team was still uncertain what caused a pit-road explosion that blasted the #27 Chevy driven by Paul Menard in the late stages of Sunday's NASCAR Sprint Cup Series finale at Homestead-Miami Speedway. Childress, involved in the sport either as a driver or team owner for decades, remarked he'd never seen anything like it. "No, never have," Childress said Monday at a luncheon before the awards ceremony for NASCAR's Nationwide Series and Camping World Truck Series. "I've seen tires blow out before sitting right there on pit road, but nothing that turned into a fiery explosion. And we don't have the answer to it yet, so it's really hard for me to comment on what happened." Childress said his team would investigate the incident back at its Welcome, N.C., race shop and report its findings to NASCAR's research and development department. "It caught on fire on the race track and built a lot of heat, tremendous amount of heat -- about like holding a blow torch on it with the wind blowing under the car and everything," Childress said Monday. "It blew the whole hub, brake rotor, everything off of it. It didn't blow a tire, and that's why we've got to find out why it blew everything off the car." Childress said the impact raised the hood and blew out the car's floorboard. While the damage to the car was severe, Childress said he was thankful that Menard, his crew and nearby NASCAR officials were uninjured.(NASCAR.com)(11-19-2013)
Based on this info I'm going to say that combined with normal axle heat the fire superheated the read end oil and vapors from the oil exploded the axle at the weakest point.
Pure speculation but we shall see.