Okay off the top of head these are the things I'm thinking.
1. There has to be a no fly zone in that area for that area, which means a pilot either willingly violated it risking getting shot down or flew high enough for some damn good parachutest to glide to the building in the dark.
2. Enviromentalists? not likely, What pilot would risk his FAA license to pull a stunt.
3. Al Queda likes the dramatic.
4. Have to be pretty damned skilled to do this next to a harbor city with the kind of winds you'd face.
5. What is generally on the roof of buildings.... HVAC systems.
6. Its a federal building, a known target for Al Queda
7. IF this story is true it would be blacked out for national security reasons. IF so.... We may be either very lucky or too late if anyone is in that building.
Praying it is not true.
If not verifiable, then could be a feint.
IF the story is true... (huge IF)
I'd say we can find the mastermind for the operation by looking for the guy who bought huge life insurance policies on the jumpers.
As described, this is truly not something anyone in their right mind would attempt.
well.. , #188, that makes me feel better ... not