Formula 1's Brazilian Grand Prix was red-flagged just before half-distance after a heavy crash by Franco Colapinto.
Running in 16th, Colapinto crashed coming onto the main straight on lap 32 as the field was under safety car conditions due to the rain that had plagued the race becoming more intense. The Williams driver, who had been supported by thousands of Argentinian fans, escaped unhurt.
The red flag jumbled the order of Interlagos' race, with drivers who hadn't yet pitted for new tyres rewarded by being allowed to change tyres before the restart.
That includes the new top three; leader Esteban Ocon for Alpine, Red Bull's Max Verstappen and the second Alpine of Pierre Gasly.
The early running had been led by George Russell, who passed polesitter Lando Norris at the start.
Russell and Norris both pitted under a virtual safety car just before the red flag period, which put them down to fourth and fifth. Right before the safety car came out, Norris passed Russell for fourth.
Both drivers, as well as the RB cars of Yuki Tsunoda and Liam Lawson, are under investigation for leaving the grid during the aborted start, which will be resolved after the race.
In the first part of the race, Verstappen had already moved up from his 17th grid position to sixth, threatening Ferrari's Charles Leclerc for fifth.
Colapinto's accident caps a disastrous day for Williams, with Alex Albon unable to make the start of a crash in Sunday morning qualifying.
Aston Martin's Lance Stroll failed to make the start after spinning out on the formation lap, which triggered the aborted start that will be investigated by the stewards and reduced the race distance from 71 to 69 laps.
Hulkenberg, who triggered the initial virtual safety car that invited the majority of the field into the pits, retired after being black-flagged for continuing after receiving marshal assistance.
Teams had been informed by race control the restart would be a rolling start, with a resumption at 2:02pm local time.
