To get the building down you need to break the four pillars at the front (facing the bay). Takes a few tank shell hits, quite a few rocket hits and about 12 C4 on each. When each is done you will hear a rumbling boom. After the last one is done, about 15 seconds later it will start to go.
With the bomb there should be three locations, A B & C. Take it to one of those and boooom.
With the bomb there should be three locations, A B & C. Take it to one of those and boooom.