I was told back ~20 years ago that the building with the fake dropcloth facade was a Kodak lab back before MIT acquired it, and contained some exotic chemical contamination that was tough to deal with (Like, stuff that was never made in sufficient quantities to even have an MSDS or any official word on how to get rid of it). MIT has been letting the chemicals diffuse/degrade for decades. Not sure if it's true, just apocryphal. Glad to see it finally getting dealt with.