INDIANAPOLIS -- The investigation into the crash that killed race car driver Tony Renna at the Indianapolis Motor Speedway will be hindered by a lack of visual evidence, an IRL spokesman said Thursday.

Because Wednesday's crash happened during a test session for Firestone Tires, there was no video or still photography to document the event, John Griffin said.

"Obviously you don't have eyewitnesses. You don't have photographers that would work during a typical event weekend," Griffin said. "From that standpoint, we are challenged."

Renna, 26, was on his fourth lap when his G Force-Toyota crashed as he came out of the third turn on the 2½-mile oval. Team owner Chip Ganassi said the car did not hit anything before Renna lost control, went airborne, cleared the wall and crashed into the catch fence.

Renna was taken to Methodist Hospital, where he was pronounced dead on arrival.

Speedway spokesman Ron Green said the investigation will involve officials from the IRL, the speedway, Ganassi Racing and Firestone Tires.

"The process can be challenging, but that's why you involve all the different groups, the facility, the sanctioning body, the team, the tire manufacturer," Green said. "You involve as many groups as you can, because they all bring a level of expertise to the effort."

There is no timetable for the investigation, which has already begun, Griffin said.

The timing of the crash could not have been worse for those investigating the wreck.

Because Renna was killed during a test session at the end of the IRL season, few were around to start what figures to be a long look into exactly what happened, Green said.

"It came at end of season, so some of the key people who will be involved in this investigation are out of town," Green said.

Many are in Orlando, Fla., for Friday's Champions Celebration -- the league's annual awards banquet -- at Walt Disney World.

IRL President Tony George met with Ganassi and Joe Renna, Tony Renna's father, on Thursday, Griffin said. The three determined the festivities should go ahead as planned.

"All three felt it was important to move forward," Griffin said.

Despite the lack of a visual record, Griffin said, officials will have other means at their disposal, including the so-called "black box" in the car that records key performance information.

"We can collect a lot of data from the cars, thanks to technology, and hopefully be able to garner a lot of information from that," he said.

A Ganassi spokesman said Thursday the team would not have further comment on the crash for the immediate future.

Renna, who George called a "rising star" in the driving ranks, was the first IRL driver to die in a crash since Scott Brayton in 1996 at Indianapolis.