My girlfriend was playing this, and she had made it though the point where she gets the battery from the machine. She was going back up to give the batteries to the guard but she tried to go back to the elevator on the outside of the building (for the second time.) Unfortunately it ran out of gas, but none of the things needs to get it from the kitchen were available anymore. I think that she's stuck. Is there any way around this short of starting over (or, had she saved the game more regularly, restoring?)
I know how this part of the game is solved in the "you shouldn't have done that" sense, but it sucks that she's trapped.
Just use the tube again.