Like Cain said, did you notice any air bubbles in the bulkhead? A " nose dive" landing should not cause such a break. Was the tower seated all the way onto the bulkhead? If not the tower won't have a lot of support and will flop on the bulkhead. Did you happen to overtighten the bottom 2 screws and strip them out? Or if the tower wasn't seated all the way the bottom 2 screws might have barely been engaged.

The only time we broke the bulkhead (before revisions) in that area was when we landed upside down directly on the tower while the car was moving forward, or catching the underside of the drivers stand after jumping off the track.