Sorry for the loss. "playing' and the baths were probably not the best idea to begin with.. it is possible if the Uro was out of its enclosure enough that it picked up some kind of parasite causing internal issues..not really sure just a guess. Has the other Uro shown any signs of problems? If they were housed together I would keep an eye on the other, also look at environmental factors. temps, humidity, food, uvb, etc