They'd been doing work on 493 Myrtle Avenue between Hall and Ryerson in Fort Greene, the building in the left-hand picture with the Vesper Bar & Lounge -- that little empty lot between 493 and Sushi Kool was filled with scaffolding, and someone had complained and obtained a buildings department violation against the owners for unauthorized construction earlier this month. But such issues are addressed a little more slowly than they should be, and yesterday around 2 p.m. the facade of 493 buckled, then the left wall collapsed into the scaffolding. Turns out there was a three-story crack in the wall that the owners seem to have been trying, in their own way, to address (the owner says the DOB approved his efforts and saw no need to evacuate). Four people are reported injured, but only one seriously enough to go to the hospital. Officials say the building next door, 491, will have to be evacuated and torn down now. Photo (cc) fixbk.