The dramatic explosion of bodywork on Romain Grosjean's Lotus during FP2 was down to the failure of a "bodywork fastener", also known as the bit that keeps the engine cover attached.
The engine cover of the Lotus flew off as Grosjean drove down the pit straight and disintegrated behind the car. The Frenchman cruised back to the pits where the car was repaired before being sent back out.
"Romain's car suffered from the failure of a bodywork fastening and the resultant bodywork disintegration and dispersal," technical director Nick Chester explained.
Grosjean used the failure as an opportunity to promote one of the team's sponsors this weekend.
"It was a convertible car option!" he joked. "I think it's just a small part of carbon that probably broke and then air went into the engine cover and it just made a big Mad Max explosion. I saw it in the mirror, for some reason I was looking in the mirror at that time so I saw it live, and I braked early and radioed to say I had lost something.
"I thought it was a small panel initially and then I drove the lap quite slowly and the car was undrivable. I returned to the pits and that's when I saw it was more than just a small part."