My son was driving on the freeway and went to change lanes and all of a sudden the power steering system stopped working and he told me after the fact that it locked up and he could not turn the steering wheel so he hit a guard rail and flipped the truck on its side. It caught on fire instantly and he was lucky to be able to get out. A passerby stopped while the truck was on fire and held the passenger door opened for him as he climbed out. If there were any children in the vehicle, they might have not been so lucky! Could have killed my son and anybody else on the road that early morning. Should be a police report. No system failures at the time.