Journal photo / Bob Thayer
Miami Mayor A. Manuel Diaz, left, and Boston Mayor Thomas Menino chat Friday as mayors, support staffers, vendors and lobbyists arrive for the first day of the U.S. Conference of Mayors meeting. Their gathering, however, has been overshadowed by picketing firefighters involved in a contract dispute with conference host, Providence Mayor David N. Cicilline. Keep up with coverage of the mayors' meeting via the 7to7 newsblog.