IndyCar officials yesterday determined British driver Dan Wheldon was killed by blunt force head trauma after colliding with a fence post that lined the Las Vegas Motor Speedway track.
The two-time Indianapolis 500 winner was involved in a multi-car pile-up in the final race of this year's season on 16 October. IndyCar has spent the last two months piecing together all the evidence to determine the cause of Wheldon's death at the age of just 33.
Critics had previously queried the speed of the cars, the quality of the chassis, the short 1.5-mile high-banked oval at Las Vegas, and the number of cars involved, 34. All, however, have effectively been dismissed, and instead it has been suggested the accident could have occurred at any track, at any time.
The IndyCar chief executive, Randy Bernhard, said: "Whilst several factors coincided to produce a perfect storm, none of them can be singled out as the sole cause of the accident. For this reason it is impossible to determine with certainty that the result would have been any different if one or more of the factors did not exist."