Three days after the accident, series' organisers with assistance from the Automobile Competition Committee for the United States, the United States' national governing body of motor racing, and motorsport's world governing body, the Fédération Internationale de l'Automobile, began subjecting the race to a full investigation. The results of the investigation into Wheldon's death were released on 15 December 2011. According to the report, there was no single cause for Wheldon's crash. Contributing factors included the catchfence around the track, and the unlimited track movement while racing that increased contact between cars, making it difficult to predict what would occur around the drivers, and increased the likelihood of a major accident. "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."