A float-Helio caught on fire in Beluga lake a few days back and there is nothing in the AIN reports. Local story is that the old gal ( in her 80s) was taxing up to the dock and after shut-down the wind blew her backwards too far. She tried a re-start and as you know the Helios have a carb that is like a pressurized throttle body. Anyway the engine compartment somehow burst into flames as she was floating around on the lake. The DOT guys had to come over on a boat to help out. No injuries and all the hoses and wires are toast. The carb looks pretty scorched.
Now that I think about it, a flooded engine fire is more possible on floats than wheels due to the chances of having hot restarts during docking.