Remember the f117's that were flying around off the west coast a few weeks ago?
Think gbu 27, not gbu 28…
All they'd have to do is put the new void sensing fuze on it.
Old video, old fuze.
New fuze designed for that bomb body:
https://www.nationaldefensemagazine.org/articles/2018/2/28/air-force-moves-ahead-with-void-sensing-fuze
Oh, also note this placard on the wall of the At&t building.
Extended burn was probably a secondary. They had something on site that was flammable as hell and enough of it to need to warn the fire department about it, which is typically 2001 lbs or more.
No it wouldn't. Cold war era at&t buildings are all hardened. Thus the need to use a bunker buster.
See image.