Were playing this game now, and now were stuck,, killed everyone but sandman and the others don't move.

Im in mission find the president and bring hem back. Mission objectives. There is nobody left to kill, and now I just keep walking but everywhere is a dead end. Its where the rails of the train are,and i'm  keep circling around. Whitout any progress.

Can anyone help? Because there is a follow, but they are just keep on staying in the alivator..

And there is no talking what so ever.

Thank you so much.