INDIANAPOLIS, IN, AUG 29 - Thirteen-year-old Peter Lenz was killed during morning warm-up for Sunday's Moriwaki 250MDH race on the undercard of the Red Bull Indianapolis Grand Prix.Lenz crashed on the warm-up lap and was struck by a 12-year-old as he tried to get off the track. The teen-ager from Vancouver, Wash. was transported to a local hospital where he was later pronounced dead. The cause was blunt force trauma, according to the Marion County coroner's office.A posting on Lenz's Facebook page read "Peter passed away early this morning when he was apparently struck by another rider. He passed doing what he loved and had his go fast face on as he pulled onto the track. The world lost one of its brightest lights today. God Bless Peter and the other rider involved. 45 is on another road we can only hope to reach. Miss you kiddo." The posting was signed by his father Michael. He is survived by his parents and two sisters.Texan Colin Edwards was Lenz's favorite rider. He raced with the number 45 that Edwards used much of his career, and also wore an Edwards replica Arai helmet."Our hearts go out to the parents, family and friends of Peter Lenz," Speedway CEO Jeff Belskus said in a statement. "Words cannot adequately express the sadness of our company and our employees about this tragic incident, and Peter is in our thoughts and prayers."The Lenz family released a statement that read, "Peter Lenz passed away this morning from injuries sustained from a racing accident. On behalf of the Lenz family, we would like to thank Peter's friends and supporters for all their help through the years. We are deeply saddened by this tragic loss, but know that Peter is racing even faster in the sky. Our thoughts and prayers are now with the other racer and his family, who were also involved in this tragedy."The MotoGP podium finishers were asked if the track was too difficult for someone that young."No, not at all," Monster Yamaha Tech 3's Ben Spies said. "You know, I wouldn't say that at all. It's a normal racetrack, and, you know, racing incidents happen and as unfortunate as it is, it is a horrible thing."Like I said, I didn't know him really well, but I had spoke to him once on the phone and sent some things to him. But, no, from what I understand, it was a pure racing accident, and it's happened before to people. The fact is, it's going to happen again at some point to somebody and we hate it, but we know what's going on when we put a helmet on; we know what can happen. That's it."The USGPRU race was restarted after a brief delay. The rest of the program also ran, though the Moto2 race was shortened to 17 laps from 26 after a pair of multi-rider crashes in turn two on the opening lap.A number of riders, including Casey Stoner and Valentino Rossi, were critical of the bumpy race surface, which was greasier than normal because of Sunday's heat. But there was no indication that the track surface played any part in the accident.