Along with falling through the subway grates and getting pushed in front of a train, the fear that the blocks and blocks of scaffolding we walk under every single day will just crumble on our heads is omnipresent. It happened today at Seventh Avenue and West 40th Street, injuring at least three people near Times Square. Emergency crews reported immediately to the scene, as did Instagrammers, while paranoid New Yorkers were reminded once more: Yes, it can happen.