IndyCar has launched an investigation into the crash which killed Dan Wheldon in Las Vegas earlier this week and hope to have a preliminary report within weeks.
Wheldon won the the Indianapolis 500 twice, died when he was caught up in a chain-reaction crash involving 15 cars at the Las Vegas Motor Speedway.
IndyCar says the investigation will seek to discover if speeds at the Las Vegas track were too high or if the field was too crowded.
Some drivers had predicted a chaotic race on the oval circuit in the lead up to the race.
The circuit had been reconfigured to add progressive banking designed to increase side-by-side racing, which can be particularly dangerous in open-wheel races.