second gunship encouter (under bridge)

[BigJack]

im under the bridge, destroyed the second gunship, and now i seemingly have nowhere to go. Rubble has fallen down to block a door which seemed to lead to nowhere in the first place. WHAT IS GOING ON AND WHERE DO I GO???

[Duracell]

Trek back to the other side of the bridge and jump back in your buggy and go accross the bridge (mind the train)