Firstly, McLaren is "pleased to confirm that... Fernando Alonso is making a solid recovery in hospital," and that's the most important part. The statement goes on to say that "he is being kept in hospital for further observation, and to recover from the effects of the medication that successfully managed his routine sedation yesterday."
From there picks up the fight against rampant speculation. Though Working confirms that it has yet to determine the cause of the accident, it vehemently denies the rumor that Alonso passed out behind the wheel after having been shocked or inhaled toxic fumes from the hybrid powertrain's batteries. "Our data clearly shows that he was downshifting while applying full brake pressure right up to the moment of the first impact – something that clearly would not have been possible had he been unconscious at the time."
The rumors were fueled by first-hand accounts, particularly from his arch-rival Sebastian Vettel, suggesting that Alonso was slumped over before veering suddenly off-track and hitting the wall. They weren't helped any by the veil that hid Alonso from view as he was removed from the wreckage to be taken first to the trackside medical complex and then loaded onto a helicopter to be taken to the hospital. But the evidence seems to point towards the strong and shifting winds as the culprit, as other drivers reported being tossed around by sudden gusts as well.
"Our data also confirms that Fernando's car struck the inside concrete wall, first with its front-right wheel and then with its rear-right. It was a significant lateral impact, resulting in damage to the front upright and axle," McLaren described the incident. "After the initial impact, the car slid down the wall for about 15 seconds before coming to a halt. All four wheels remained attached to the car, but no damage was sustained by the bodywork or crash structure between the front and rear wheels."