Underbelly definitely needs to come off, which should give access to the P-trap area as well. You'll probably find some water in there too. It should be covered under warranty. I have a feeling a lot more water soaked items will be found. Bad thing is, that is such a simple thing to go wrong, yet can cause a ton of damage. Might want to check everything else to make sure there are no more water leak gremlins. For now, break out the fans and maybe a dehumidifier, try to dry it out and prevent any further damage.
In the future, that's one of the many things that should be done in a PDI. We take things apart to access everything we can to prove that nothing leaks. For those areas we can't access, we start cutting walls and start installing access panels. I caught most of our plumbing leaks before we stayed the first night in ours.
John and Rebecca Dickson
Emma-7 / Little John-5 / Iva-1
Full Timing Again, Rev B
2013 Ford F-350 Lariat CC LB PSD
2015 SOB TT - With OC's Awning Poles (#8)
At least in Heaven, RVs will be perfect, and I won't have to keep fixing them.