Drag racing is more than just mashing a pedal.
We're not entirely sure how this accident happened, and it's likely that we'll never know. The driver starts off by having some difficulty backing, which happens sometimes with drag cars. But the car then somehow ends up in a forward gear, and get's propelled into a wall. The driver was apparently knocked out on impact, with his foot on the accelerator. So the car just keeps on going until the tires pop, and a bit more after that.
The driver obviously suffered some minor injuries, but will recover. It really could have been a lot worse.