I had friends over who shoved a bunch of shit down the sink a month or so ago. A clog did not seem present at the time.
A few mornings later, I left for work and ran a load of laundry (a big load).
While I was gone, the washer drained many times, hitting the clog under the house. Backed up into the kitchen sink and flooded all over the house, ruining tile and hardwood.
I did not discover this until around 6PM.
I am now living on subfloor, with new bamboo hardwood slowly going in throughout.