Kiwi IndyCar driver Scott Dixon narrowly avoided opening lap carnage in a drama-filled race at Pocono Raceway, which saw five cars involved in a serious crash.
On turn two, Takuma Sato, Alexander Rossi, and Ryan Hunter-Reay were racing three wide - just behind Dixon - when the incident occurred.
Japan's Sato cut across the track, making contact with both Rossi and Hunter-Reay, and the impact sent the three cars off course.
Sato's car then collided with Felix Rosenqvist, sending the Honda driver airborne. James Hinchliffe also hit the wall, while trying to avoid hitting Sato, Rossi and Hunter-Reay's cars.
All five drivers were eventually cleared of serious injury, although Rosenqvist - Dixon's teammate - was taken to a nearby hospital for further evaluation, before being released.
Rossi, Hunter-Reay and Hinchcliffe all resumed the race after repairs, although all three were several laps down and out of contention for the win.
The race resumed 45 minutes later, with some drivers criticising Sato's tactics, referring to another scary incident last year, which left Canadian driver Robert Wickens a paraplegic.
"I can't even begin to understand how, after last year, Takuma thinks that's acceptable," Rossi said. "It's disgraceful."
On Twitter, Wickens said IndyCar should no longer race at the track.
"It's just a toxic relationship and maybe it's time to consider a divorce,'' he wrote. "I'm very relieved [to my knowledge] that everyone is okay from that scary crash.''
In 2015, Justin Wilson died from injuries suffered in a race accident at Pocono, but defending IndyCars champion Dixon defended the track from criticism.
"These things can happen at lots of the tracks we go to," he said. "This place has had a rough run with some of the incidents and weather.
"It is one that rewards you when you get it right and I feel sorry for everyone that works here."
Once the race resumed, Dixon managed to take the lead, but eventually settled for second, when officials called the cars in with 128 of 200 laps.
Black clouds formed over the track, which led to the race being red-flagged.
When the race ended, Australian Will Power was leading, so he was declared winner.
The result helps Dixon's championship cause. He remains fourth in the standings, but is only 52 points behind series leader Josef Newgarden.
American Newgarden leads Rossi by 35 points, with Simon Pagenaud 40 points.
With just three races remaining in the 2019 season, the series moves to Madison, Illinois, for the next race at Gateway Motorsport Park.
Over the weekend, Australian Supercars organisers announced Rossi and Hinchcliffe would compete in October's Bathurst 1000 as a wildcard entry.