Disclaimer: There's a lot of stuff in here that I'm not expert in; I've done my best to do a little research and make the details sound plausible, but that's it. Please suspend disbelief if you can as I explore this little idea.
I do not own anything to do with Glee. The song used was written by Jonathan Cain.
Day 0: Disaster
The Euler Building in New York. Named after a mathematical finance company who in turn had taken the name of a pioneering mathematician who would surely have cringed at what uses they had for his logic. A target, that day in 2018, for a set of financial profiteers who wanted to get an edge on their competition, and weren't above using very illegal means to do it.
Like computer espionage of a competitor. And then, to cover their tracks, setting a series of bombs in the competitor's building, to knock out their systems, fry their servers and backups, and distract key personnel.
The electromagnetic pulse generators were set under the offices on the fifth floor, with some minor explosives to distract the staff and cause evacuation. Bombs surrounded the servers, deep in the bowels of the building. A storm was coming in from the sea, high winds, but this seemed of little consequence to the explosives crew as the countdown proceeded to the appointed time.
At one-thirty in the afternoon, the pulse blew the power and electronics, followed a minute later by the shielded explosives that the pulse triggered. The saboteurs congratulated themselves on a job well done.
Then it all started going very wrong.
Almost seventeen years after 9/11, everyone in New York, particularly in the financial community, knew to evacuate a building at the slightest sign of trouble with the structure. The Euler was also quite a narrow building, and the occupants of the fifty floors above ground all got out without difficulty.
The food court below ground, right above the servers, was a different matter. Its floor had been mangled from the blasts, blocks heaved up from the force and sunk down to the floors below. The pulses had cut access to even the backup generators, so the place went completely dark, everyone screaming as they felt the blasts but saw nothing. Many were badly hurt as the floor buckled beneath them and furniture flew, nobody able to see anything coming.
Once the blasts subsided, gradually people pulled out their phones to call for help. But the EM pulse had ruined those too, for the most part, though some of the screens still worked for a while to give them a little light. What they saw was a mess, bodies, furniture, slabs of floor and ceiling. And no way out, the stair supports cracked and the stairs themselves tumbling down. People on the stairs or too close to them had been killed on impact.
All they could do was listen to each other cry in pain and for help, try to assist and comfort each other as best they could, and hear the creaks of the building above them as it swayed in the wind.
The investigation later revealed that the construction materials had been inadequately reinforced, everyone involved cutting corners to make a quick buck. With some of the supports bomb-damaged, the remaining structure wasn't sufficient to withstand the storm winds that were now blowing in from the sea. An hour after the bombs blew apart the basement to trash the server farm, the Euler Building crashed down, smashing into the side of the building next door and filling its own basement with debris, killing almost everyone who had been trapped in the food court.
Almost.