Criminologists George Kelling and James Wilson, produced a theory called “Broken Windows.” They stated after extended studies within neighborhoods, the simple yet factual result of windows that are broken and not repaired send a message that no one cares or no one is in charge of the home or neighborhood so crime is inevitable and becomes rampant.
People sleeping in doorways or hallways of apartment buildings, deviant human beings panhandling for whatever they can get, urinating in public, graffiti on walls of once respectable buildings. Entering the subway you're in an uncontrollable environment that seems to have little or no enforcement, and you're on your own until your back above ground and in the light of day.
This deterioration comes slowly with just the “broken window,” which gives the message no one cares or is in control, but soon becomes a complete breakdown of neighborhoods where many are trapped or enticed into. People complain but the system seems not to care.