I didn't make it!
How do you get on the roof at the start of the game...I assumed you blew the tank and climbed up the rubble but that has not worked so far....thanks,Bill:(
Once you get to the heavy machine gun that is placed in fron of the door where the cars are,there is a sidewalk to the far left. You go down that sidewalk,there will be a truck that comes forward then slides sideways. Well right next to the truck is a ladder,climb it an walk along the ledge of the building till you come around a corner,then there is a door,an in you go ;)
or look here