Interesting story but I have a bit of anecdotal evidence to share. Back when I was a Freshman at UIUC in 1989, I was given a campus tour and told that one of the buildings there was designed to collapse outwardly in order to protect the equipment in the basement. That equipment was a national computer network (not yet called the internet!)

So at the very least, the origin of this story predates 1991 by at least two years.

I don't recall the name of the building but here it is on Google maps.

https://www.google.com/maps/@40.106201,-88.2268272,3a,75y,91...

Edit: It's not clear from my original comment but the reason for collapse would presumably be a nuclear strike. I remember this because this was a time when we grew up with a constant fear of a Russian nuclear strike and I couldn't help but wonder why anyone on earth would want to nuke Champaign.

Edit: Ah, here we go! It is the Foreign Languages Building (FLB), later renamed. I remember having to trudge here at 7ams on snowy winter days to listen to Japanese language cassettes.

https://uihistories.library.illinois.edu/virtualtour/maincam...

Edit: And here's a contemporary article about the FLB, which also cited some of the crazy rumors about this building.

https://imgur.com/HXenjnt.png