Forum:Can't get on the monorail to plant the bomb

So I'm trying to work for the Legion, and I'm doing I put a spell on you. I picked up all the bomb equipment, I put it in crenshaw's locker, and killed him, but I cant get onto the monorail to plant the bomb. everytime I go up to it, theres an invisible wall and it gives me the option to travel to the strip. how do I blow up the monorail?