Was trying to get this finished before 9-11 but had a lot of issues staying under the max parts number. Then was going to have vehicles driving in both lanes but some structures where pushing vehicles. So here it is plenty of places to go many roof tops, parking garages etc:
The Twin Towers courtyard has stairs and doors of course you can't go in towers just to give it a more realistic look.

Hope you like it have fun!

This is a update forgot to add the trigger to bring the north tower down from 10 floors to one. If you look at the North tower at the stairs in a bush you will see a fire extinguisher if you shot that it will vaporize all levels but one. During play if you don't want tower to come down most people won't even know it's there.