slide out plywood is rotten

[jimkottke]

I have a 2005 big sky 3670RL and under the couch where the carpet is the wood is black and rotten. I cannot find out where the water came from. All the seams are caulked. I tried using the hose and did not see any water leaks. The walls are ok only the floor. This is 12/24 inch area of the floor in the corner. Has anybody had a problem like this?