Recently, I had houseguests who didn't realize that water was spilling onto my hardwood kitchen floor from the counter.
Bill had some firsthand experience a few months ago when the flush handle stuck on his toilet and the water continued to run.
[...] to compound matters, a plugged sewer line caused the toilet to overflow.
The next three weeks brought a parade of water damage specialists, insurance adjusters, and carpet and hardwood floor contractors.
Water always finds its lowest level and, depending on how much was spilled onto your floor and how long it pooled, we would be willing to bet that more than the one board was affected.