Renna investigation proves inconclusive

The IRL pointed out that there are components not fitted with sensor equipment and that it is therefore impossible to rule out mechanical failure as a cause of the accident. "The list of items on a car that can fail, and that aren't monitored by sensors, is significant," said senior VP of racing operations Brian Barnhart. "Several of those failures could cause a crash. In addition, unforeseen factors can also come into play and contribute to the cause of the accident."

The accident review revealed that Renna's car entered Turn 3 at 227mph. At a point just past the apex of the turn, the car executed a 90deg half-spin to the left into the infield grass. As it travelled sideways over the grass, air beneath the car caused it to lift into the air. While in the air, it spun approximately another 30deg to the left.

The car traversed the track through the air and made contact with the debris fence on the outside retaining wall in Turn 3. IRL officials said it appears that the most significant damage to the car and the fatal injuries to the driver were caused when the bottom of the monocoque made direct contact with one of the debris fence support posts.