Federal highway safety investigators are reviewing 25 cases over two years of steering knuckle fractures involving 2003 model year Hummer H2s, according to the Sacramento Bee. The component failure has resulted in several vehicles losing front wheels and subsequently crashing. When testing an H2 in 2002, the the Bee's auto editor Mark Glover experienced a similar failure where a wheel fell off of the test vehicle. GM denies there is any problem with the component, which holds the steering arms in place. The automaker says the failures are the result of "crashes." In the case of Iris Ziroli, bumping a post led to the complete loss of a wheel. "I thought I was so safe because the H2 is so huge and strong," Ziroli said. "The way that Hummer fell apart in that drive-through was uncalled for." In 2003, GM redesigned the component. However, the automaker denies it was due to failures. According to GM product safety spokesman Alan Adler, GM always wants to "improve its products."