Rotted base sill plate

[Arjun K.]

I closed a house in March. it recently flooded a little over new floors. Call it ~$5K damage. It now looks like the base plate was rotted away, and in some cases gone ouright where you can see sunlight from the interior. This suggets flooding may have happened in the past as well, and seller did not disclose (I do not know for sure). I had a home inspection, but that inspection did not catch this problem at the time. What recourse do I have?