I've watched this video clip sometime back. It was the most horrendous crash that i've seen. Sickening to some extent.
Anyways, just to clear the air. The F1 driver that crash into the marshall was Tom Pryce and they were racing at Kyalami at South Africa when one of the cars caught fire and needed attention from the marshalls. Back then safety was not a priority and these drivers don't give a fuck when there's an incident somewhere and probably won't slow down too. So anyways this marshall was on his way to the car with that extinguisher but didn't realise he was too close. Tom Pryce subsequently smashes into the marshall killing him instantly while the extinguisher hit Tom on his head, also fatally injuring him. The car went on straight to crash into another driver as Tom was either dead or was already unconscious.
Its a sad chapter in Formula 1 when this sort of horrible death occur. It just goes to show how safe F1 is nowadays.