I had the exact thing happen to my 2010 Fuzion bedroom slide.
The angle iron is attached to the slide floor by carriage bolts run up through the floor and bolted into the angle iron, which is bolted to the slide actuating cylinder. The underside of the slide floor was protected by a waterproof covering that was glued to the floor.
That's how ours was.
Howard and Peggy
"Don't Panic"