Williams says it will urgently investigate the mechanical problems that caused heavy crashes for both Nico Hulkenberg and Rubens Barrichello in Monaco.
Hulkenberg slammed into the wall in the tunnel on the opening lap due to a front wing issue, while a breakage at the rear of Barrichello's car sent him spinning into the barriers as he crested the Beau Rivage just before half-distance, taking him out of ninth place.
"That was not a good day for the team after a promising start for Rubens," said technical director Sam Michael.
"Nico had a problem with the clutch paddle on the steering wheel during the formation lap. He then had a failure with the front wing mounting on the first lap of the race.
"Rubens had a fantastic start and was running in sixth when he started to experience poor handling after his stop. Eleven laps after his pitstop, he had a failure at the rear end of his car.
"We need to get all the parts back to the factory in order to identify correctly what components on both cars caused the failures. We have quite a bit of car damage to repair, but we're making progress with performance and look to further that in Istanbul."
Barrichello said the incident had come as a shock to him, although the car's handling had been deteriorating prior to the crash.
"What happened today was a real surprise," he said. "I had such a good start but the car started to feel really strange after the pitstop.
"The steering wheel, in particular, didn't feel normal. The problem continued to get worse and then I crashed."
Hulkenberg was equally bemused by his accident.
"I'm then not entirely sure what happened in the tunnel," he said. "The car felt odd one minute and the next I was in the wall."