Red-Eared has died

Question
I've had my 2 red-earred sliders about 2 years.  I noticed my turtle acting limp last night.  Seems it would float and crash into the side of tank.  Almost like it couldn't see--even through eyes were open. I think it had a stroke.  Was on my way to veterinarian, but it died on the way.  What could have happened so suddenly.  My other turtle is fine.
Thanks for your help.


Answer
Floating and poor swimming control is a common sign of pneumonia, but can be many other things.

I would take active steps to protect the other turtle. Try a good site like http://www.redearslider.com to see how what they recommend and what you are doing compare and see if there are things that can be tweaked or improved for the other turtle.

Good luck!