Robert Wickens crashed his Schmidt Peterson Motorsports-Honda during practice for the Indianapolis 500, after brushing a wall, triggering what appeared to be suspension failure.
After a brief rain delay the 3h30min session was just 19mins old, and the Canadian rookie was lying 11th on the speed charts with his third lap.
On his fourth lap, he slid up into the wall exiting Turn 2, and further down the backstraight a component appeared to fail, spitting him sharp right into the wall again.
The car sustained heavy front end and right-side damage, but Wickens was able to step out unaided.
Within five minutes he had been checked at the IU Medical Center, and cleared to drive.
Wickens told IMS Productions: “I caught some oversteer in [Turn] 2, really late in the corner, and I caught it. I thought I got away with a big save. It actually oversteered again. I ran out of track.
"The suspension was damaged. The car went violently driver’s right. It caught me off guard.
"It sucks for the guys. They have a lot of work ahead. Today was an important day for us to build a good car. Instead I gave them a lot of damage. Only my second or third lap, so hard to get a good reference."
Team co-owner Sam Schmidt added: “We saw a couple replays. He got loose in the middle of Turn 2. Not sure if we had a low tire.
"It’s certainly a setback. The momentum from his season was building. But better today than raceday; hopefully nothing too major.”
Wickens has qualified 18th for his inaugural Indianapolis 500.