On Lap 32 of 71 Magnussen was snaking his Haas through the Esses in the second sector when he appeared to suffer a left-rear suspension failure, which sent his car hard into left-hand barriers at Turn 9.
The heavy hit destroyed Magnussen's car, but the Dane was able to climb out of his wrecked Haas unaided.
After a brief safety car period the race was red-flagged with 36 laps remaining, due to the enormous amount of debris.
Max Verstappen reacted to Magnussen's crash by pitting for new hard tyres but retained his lead ahead of Ferrari's Charles Leclerc and Mercedes driver Lewis Hamilton.
Carlos Sainz was running fourth in the second Ferrari followed by AlphaTauri's Daniel Ricciardo, who comfortably kept up with the frontrunners' pace in the top five.
Sergio Perez shocked the home fans by crashing out in Turn 1 of the first lap after contact with Leclerc.
More to follow...
Source: Autosport