So far, there isn't any indication that there was in fact a mechanical problem. The original report of a mayday call has yet to be verified. And even if there was a fuel starvation problem (like the original reports suggested), that is still no reason to loose control of the plane and centerpunch a building. This could just be a case of a couple of guys flying into a situation that was over their head. And if they thought that they were still in control, they wouldn't have gone for the 'chute.