Recently at a Chipotle in Kentucky they were forced to close up for some time after staff walked off the job, including a manager, who allegedly claimed that the staff had been cussed at, threatened, had food thrown at them, and endured other horrible working conditions.
From restaurants to airplanes there are increasing instances of customers getting angry and violent with those who are trying to do their job and it is getting the point that for some they are just simply not going to do the job any longer. Being a target for that sort of harassment from the public isn't worth the poor wages that are being paid out.
It also doesn't take much for one business like Chipotle to be completely shut down for the day when just a few members walk out unexpectedly. The horrible conditions for fast food workers have prompted staff at other stores to take action in walking out as well.
They closed due to staffing issues but they have reopened now. This comes several months after the Chiptole CEO claimed that it was difficult to keep people from leaving the job.