thats a chop.... you can see the straight cut edges. If that was due to the crash, the metal would have had shredded edges.
the chasis has bend completely, chopping the whole left side and roof might have been the only hope to get those people out. We always talk about these speeding incidents (there is a whole thread about that here) but people just dont get it. Every car can go fast, the question is, how will you control it if god forbid somthing like this happens.