One the local residents was saying that prior to planned demolition explosions, they've been warned to stay indoors and close all windows. Some of the treatment of those affected by the collapse appears to relate to dust inhalation, presumably simply because of the quantity of dust involved, rather than its constituents.
What the aerial photographs of the remaining building shows, is that it appears to be fairly solidly stuffed full of equipment. More a large integrated engineering installation, than the box full of equipment that most of us often think of, when the term building is used.