"The #4 climbed the left rear of the #17 and became airborne for a brief period of time," continued the report's account. "The #15 (Jay Howard) made contact with the #17 and then the #15 slid up the track and hit the outside wall with the right side of his race car. The #17 made contact with the #22 (Townsend Bell). The #22 spun and hit the wall with his left side. The #4 came back down almost on top of the #17 and both of them hit the outside wall almost as one with their right sides."
Approaching behind them at a maximum speed of 224mph, the #77 of Dan Wheldon stayed low on the race track to try and avoid the unfolding crash. But the #17 of Vitor Meira was spinning toward the infield and collecting the #59 (EJ Viso) and the #83 (Charlie Kimball) directly in front, which effectively blocked the path of the #77 that was two car lengths behind the collisions.
"Approximately 3.8 seconds before impact, the driver of the #77 reduced throttle to about 55%," the report explained. "Approximately one second later, the throttle was reduced even further, down to less than 10% and the throttle remained in this position until contact. The driver of the #77 applied the brakes for approximately 2.4 seconds prior to contact, and had decelerated to a speed of 165 mph as the right front of the #77 made contact with the left rear of the #83."
The #77 was launched airborne with G-forces of 24 longitudinal and negative 23 vertical. It rolled to the right in the air and travelled in a rearward direction in a nose up, semi-airborne state for approximately 325 feet until it made contact with the catchfence "in an inverted posture with the cockpit was open toward the fencing.
"The chassis of the #77 impacted a post along the right side of the tub, created a deep defect in the tub that extended from the pedal bulkhead along the upper border of the tub through the cockpit," the report detailed. "This resulted in angular deformation of the roll hoop that was sheared off the tub from right to left. As the race car passed by, the pole intruded into the cockpit and made contact with the driver's helmeted head.
"This impact produced non-survivable blunt force trauma injuries to Dan's head," stated the report. Despite the fact that the right front pull rod of the #77's suspension had been driven into the driver safety cell, "The suspension did not make contact with the driver, or penetrate his uniform ... Dan's injury was limited to his head injury."
The report went on to describe the next series of collisions between the #57 (Tomas Scheckter), the #8 (Paul Tracy), the #30 (Pippa Mann), and the #19 (Alex Lloyd) that had resulted in Mann being launched into the air for some 240 feet and landing upside down; and then detailed how the nose of the #12 of Will Power impacted Lloyd's left rear tyre and was launched into the air for 315 feet before landing right side up. Mann received burn injuries to her hand which are still receiving treatment, while Power suffered some compression injuries to his back from the impact that have required him to wear a brace during his recovery.
The account finished by stating: "The above analysis of the sequence of dynamic events revealed no extraordinary car-interactions or interactions that were specific to this incident that have not been encountered in other races. The impact with the fence that resulted in Dan's non-survivable injuries involved circumstances of location, direction, and orientation that were the chance result of the previous interactions."
The SAFER barrier and other safety measures that came into play "appear to have functioned as designed during the accident," and were repaired within the hour so that racing could have been resumed if directed by race control, although 13 cars had been written off in the accident.
As a result of the report's findings linking the design of the car with the track configuration as main causes, the report comments that with the introduction of the new DW12 chassis from the start of next season, "Further testing is appropriate to evaluate the dynamic between the new race car and the specific geometry of this track." IndyCar announced last week that next year's scheduled race at Vegas had been cancelled to facilitate exactly this sort of testing.