Ryan Hunter-Reay, Juan Pablo Montoya explain Pocono IndyCar crashes

Hunter-Reay, the 2015 victor, was first to crash when his Andretti Autosport Dallara-Honda snapped into a spin exiting Turn 1 early in opening practice on Saturday and hit the outside wall so hard it started to tip top-first into the SAFER barrier.

The 'domed skids' and safety flaps installed for 2016 to reduce lift in accidents appeared to do their job as Hunter-Reay's car landed back on four wheels before sliding to the inside barrier.

VIDEO: HUNTER-REAY'S BIG PRACTICE CRASH

The 2012 champion was unhurt but the chassis - which he used for his '14 Indianapolis 500 win and many other oval victories - had to be parked. Hunter-Reay missed qualifying and will start last in a back-up car.

"We were just on a qualifying simulation, trying to get as flat as possible and we just had it a little too far forward on the balance," Hunter-Reay explained.

"And the front grabbed, but just a little bit, which is what I got last week at the test here and it was fine.

"The rear just all of a sudden snapped, and once these cars get to a certain angle you dump all that air off the wings that you're relying on and you just can't do anything about it."

Hunter-Reay said his team will have to depend on data collected from the test at Pocono two weeks ago for race set-up.

He returned to action in Saturday's final 30-minute practice session and was 13th fastest.

"We had a really good test here, so this is really unfortunate that we have to reset," Hunter-Reay said.

"The part I'm most concerned about is that tub. That's our Indy 500 winning tub and we've had a lot of oval wins on that car.

"It was big, it always hurts in these cars. You never get used to it. It's unfortunate. It's a setback."

Montoya's crash at the same place caused less damage but brought Saturday morning's session to a slightly early end.

Penske was able to prepare a back-up car in plain livery for the 2014 Pocono winner in time for qualifying, where he took 15th.

"I was just on cold tyres, Simon Pagenaud was coming and we just misjudged the situation," Montoya said.

"I wanted to make sure we didn't get in Simon's way. I tried to hurry up. It was cold tyres and that was it.

"We just put ourselves in a hole again. But it's OK. We'll work through it.

"Before that it was really good. We made a lot of gains for the race. I think we'll have a really good race car."

Ganassi's Charlie Kimball also crashed at Turn 1 in Saturday practice. He got back out to qualify 16th.