Originally posted by Earth
From what Ive seen, it looks as though the object that penetrated his visor did it before he hit the wall, while he was in the turn, and he immediatly went uncounsious and hit the wall.
I think he may have hit debris from a previous crash and his tire propelled it into his visor during the turn, then he lost control and went straight into the wall.
No - the suspension piece that penetrated his helment was from the car's front right wheel that broke off in the impact - this accident was a major part of the impetus behind the introduction of wheel tethers.
The Italian manslaughter prosecution revolved around the snapping of the steering column before impact, and they allegedly had metallurgical evidence that the column snapped at the point of a weld (which was done a day or so previously at Senna's request to lower the wheel's position in the cockpit) prior to impact.
The video does show a spark from the undertray of Senna's Williams just prior to it going straight on - it could well be that the car hit debris which broke the steering column. Unfortunately the only guy who knows for sure died in the incident.
That was a horrific weekend. I remember hearing on Sunday morning that Ratzenberger had died in practice, and seeing the horrendous footage of both that accident and Barrichello's flying into the top of the catch fencing.
And then, that fearful started with Lehto getting severely rear ended on the grid, and then THAT crash - the race finished early in the morning Australian time (around 1 am or so), and I remember going to bed after the race with the report of Senna being gravely ill ringin in my ears.
I got up at 6 am to get ready to go to work and Senna dying was the lead news story. I spent about the next week in shock - and in the following weeks, Wendlinger knocked himself into a coma at Monaco basically finishing his GP, Pedro Lamy destroyed his legs after going over a fence at Silverstone in testing (I remember a great quote from one of the Lotus managers 'the biggest piece left of the car was Pedro') - it was a sickening couple of months.
If you guys remember watching the first corner worker walk up to the car and kinda jump back. I wonder what he saw????
If the medics took only a minute to get him out then they did an incredible job. I work part time at Mosport on the trackside Medical team and have removed people from crushed Formula 2000, Atlantic, and F2's and its no easy task. If his injuries were as severe as vat said then he was likely already dead. An impailed object to the brain as well as a high speed impact would almost certainly caused near instant death. At least he didn't feel it. 
