RULES WRITTEN IN BLOOD. Tenement houses have long had back porches, which originally provided landings for fire exits, a place to reeve a clothesline (somebody had to shinny up a nearby power pole to provide the outer block), and sometimes space for a chair or two and maybe some potted plants. Many tenement houses have provided fodder for gentrification, which involves rearranging the insides to provide bigger rooms and track lighting, and redoing the back porches to imitate the decks popular with free-standing houses. Set up as such, the decks provide space for social gathering on a scale not imagined by the original builders of tenements. In theory, there is a maximum live load for such a deck, although most people leave that calculation undone. Consequence: porches collapse. (The Rockford news broadcast reported a balcony failure with injuries on Sunday, details are eluding me.) Whether insurers or building inspectors will insist on more rigorous inspection of porches or the posting of load limits remains to be seen. Northern Illinois University and the University of Chicago Law School (still no mention of the accident at Crescat Sententia) have lost students, and many people have lost friends. The Chicago Tribune has extensive coverage including a report from the fire house and a reader's forum in which the second-guessing has already begun.