A HRT mechanic injured in the pits
The very end of the first free practice session saw one of Pedro de La Rosa's mechanics being hit by a car. Transported to the hospital, he reportedly does not suffer from any fractures according to the Spanish team's Twitter account.

As the drivers returned to the pits after the end of Free Practice 1, the latest television images provided by the FOM showed an ambulance stationed in the pit lane at the HRT garage. It was actually there to assist a mechanic of Pedro de La Rosa, who was lying on the ground after being hit in circumstances that are still unknown.
Fearing a broken leg, he was evacuated on a stretcher and taken to the hospital in Montreal. The initial examinations seem to be rather reassuring, according to the team’s official Twitter account: « Good news! Chess, Pedro’s chief mechanic, is still at the hospital for further tests but seems to have no fractures ». More fear than harm, apparently. Let’s hope that, unlike Chess, no other mechanic ends up in check.
Update: The HRT team stated in their official Friday release that Craig Stubley was injured during a pit stop simulation and confirmed that it was more of a scare than actual harm.