Years ago, on a trip from Sacramento, we were towing a trailer with one of my hot rods to a Goodguys show in San Diego. About 8pm my wife went to use the rest room and forgot to switch off the pump. About three hours later she got up to go again and stepped into a soggy mess of carpet. A magazine I'd left behind the faucet in the wet bar had bounced enough to turn on the faucet, not much but enough. Since we had planned on dry camping, we had 100 gallons of fresh water on board. That tank was now empty!. We spent several hours in Laguna Hills swamping out the rig...so it does/can happen....Dennis