One broken window left unfixed can invite a building's collapse into disorder

In a 1982 Atlantic essay, James Q. Wilson and George Kelling argued that visible signs of disorder — a broken window, graffiti, loitering — signal that no one is watching, encouraging more serious crime. The idea shaped 1990s policing in New York City, even though later research found only mixed evidence that disorder itself causes crime.

— Wikipedia, Broken windows theory — The Atlantic, March 1982