One day while patiently trapping a cat. We became aware of some cats that were being cared for by a woman who was a tenant in one of the nearby offices. In this colony was Jet (black Cat), Carol Anne (White/Orange/long hair) and Rusty —All had been fixed! 
She had been caring for these beautiful cats about 5-6 years. Then one day about 2 months after meeting her, we noticed the business no longer was there, after inquiring around, we realized, sadly she had abandoned the cats. We took over the care and feeding of this colony. Rusty is the only one to date currently returning to the feeding station.
We are very pleased that this kind-hearted woman had ensured they were fixed and cared for them as long as she was available. But, the ideal way to handle a colony that you can no longer care for is to reach out to local TNR groups so they are aware of the cats and can work to find a replacement caretaker.