Smashing Impact

Whenever you successfully bull rush an enemy
and its movement is stopped by a solid object or
barrier, you can deal your unarmed strike
damage to both the foe and the object or barrier,
as long as the enemy is within your threatened
area. If you performed your bull rush as part of a
charge, you gain a +2 bonus on your damage roll.
If the damage is enough to destroy the object or
barrier, you can continue to push your target the
remaining distance allowed by your bull rush
combat maneuver.