I run the washer, dryer, dishwasher, you name it when I'm not home. Accidents can happen ANY time, that's why they are called accidents.
I left the house one day, came home to water running out the front door. Opened the door and there was a waterfall coming down the stairs. Entire downstairs, except for livingroom was flooded. What happened, you ask? The water hose to the toilet broke. There are/were drains in every room that has/had water running in it, but the water came out with such force that it knocked over the waste basket, everything came out and covered the drain so the water couldn't drain down. Took me and Courtney 4 hours of straight mopping and whatnot to clean up. Only lost 2 boxes of books, but even that wasn't bad...it could have been worse. It was an accident that could not have been stopped. Now, should I have turned the water off to all toilets at night and when I left the house? NOPE!! It was an ACCIDENT!! That's why there is insurance. I refuse to live in fear and that's what would happen if I were to run around and make sure everything was off and/or not running when I left the house or went to bed at night.