I've only seen one on my last two visits. I believe I remember reading mstickmanp saying something recently about there only being one elderly specimen remaining. And yes, they did successfully breed them on at least one occasion. That offspring remained on exhibit here for many years.
Maybe this space will be used as part of the LAIR complex one day. Chinese Alligators possibly? Or the Chinese trading places with the American Alligators? Chinese gators were to have been included in the original plans.