Fallout 3 liberty prime is stuck on the bridge?

he is on the left side and just stopped. all of the lyons paladins died except for lyons and i cant find their bodies to drag them forward. my last save was way to far back and i dont want to do it all over again. how do i get him unstuck. i cant go forward because he hasnt broken all the barriers and im playing on the x-box. last time i played he didnt get stuck, WTF.