At least I assume that's what happened to this NSU. 
The outside rear wheel came off, then the car rolled over it and got launched into the air.

http://youtube.com/watch?v=PFgIzPSsFJM&feature=related

Jim

Hello Jim,

In this case it is probably not a stub axle, but instead a rear brake drum that shattered.  The NSU cars had a steel web cast into the brake drums (which hold the wheel) and the drum is then bolted to the axle. 

Perhaps equally important is the lack of a fuel cell.  Notice how the fuel STREAMS out of the front of the car !!!!

Paul
Scuderia Topolino

I didn't know that about NSU rear brakes.  Not a very satisfactory way of mounting a wide race tire.

You're certainly right about the lack of a fuel cell.  As it was everything seemed to turn out OK, but had the driver been unconscious and the car slid a bit longer and thus created a spark to ignite the fuel, it could have been a very tragic situation.

Jim