
Andretti Global’s Colton Herta also crashed, like Armstrong, in turn 1.
Gusty winds are believed to have contributed to the incidents.
Driving the blue No 66 Honda for Meyer Shank Racing, Armstrong lost control while approaching a turn, spun and crashed into the wall, severely damaging the left side of the car.
He was able to climb out the mangled wreckage and immediately was placed on a stretcher.
Medical director Dr Julia Vaizer spoke to Fox Sports after Armstrong was evaluated.
"He is awake, he’s alert, he’s doing well," Vaizer said.
"These hits at IMS oval can be really hard.
"We just want to make sure we don’t rush things, we take our time, and make the right decisions for the driver."

In a hastily prepared backup car, Armstrong put in a lap securing 33rd, meaning he will have to face off against yesterday’s three other slowest cars in this morning’s last-chance qualifier.
One of those four will not make the 33-car grid for the race.
Armstrong, 24, of Christchurch, won the 2023 NTT IndyCar Series rookie of the year in 2023.
The former Formula 2 driver spent his first two seasons in IndyCar driving with Chip Ganassi Racing.
He has two top-10 finishes in five starts this season and ranks 14th in the driver standings.
Herta came back to qualify 29th in a backup car.
Qualifying for yesterday’s top 12 continues today, including the fight for pole position.
The 109th Indianapolis 500 starts at 4.45am on May 26. — Field Level Media/APL