Only one year after opening, it looks as if the Five Guys at 1 Flatbush Avenue has closed. The business phone number is also out of service. Just last month the other Flatbush Avenue location, off Park Place, shuttered. Here’s Park Slope wondered if the reason for its closure could be an “arena-geared presumed clientele that never materialized,” which may also be the case at this location. This Five Guys was working with the Department of Transportation to bring a public plaza to this space with outdoor seating, but nothing’s happened in that regard yet.