Surviving camera was connected to a ZyXel POE switch but was not being supplied power by the POE switch. The power on that particular port failed a while ago. The camera was being powered by an external 12VDC supply.
UPDATE:
Brought the failed cameras inside to play with and found the POE...
A couple of weeks ago we had a bad thunderstorm while I was out of town. When I came home I had lost a modem (Comcast), a computer, and 2 out of 3 cameras. I put in a service call for Comcast to come replace their modem while I licked my wounds over my lost equipment. It should have been a...