I was in for an unpleasant surprise when I finally figured out where that sound of running water was coming from. I noticed it in late afternoon but didn't pay too much attention to it at that time. As the sound didn't appear to stop I did check everything inside the house but couldn't find anything out of ordinary.
The I finally realized to check the garage and storage room, and encouraged a small flood. The pipe leading to the garden outlet was leaking! The pipe runs on the wall behind storage shelves, leaking water all over those boxes of random stuff I had stored there. I quickly ran to cut out the main water and called a plumber.
While waiting for the plumber to arrive I moved all the boxes from the affected shelves into safety. Unfortunately for most of them it was already too late. The content of the boxes were soaking wet already.
After the plumber visited and did an emergency fix it was time to start going through the things I was presumably lost. The biggest loss was a substantial part of my old comic book collection. Many of the boxes were right in front of or below the leaking point.
I also salvaged a couple of boxes which turned out to contain some old IT equipment. Ruined now, but the loss wasn't that big. I think those boxes have remained unopened through at least a couple of times we have moved. And they were already old when I tucked them away into those boxes.
Finally there were a couple of boxes of old papers, mainly from our kids kindergarten and elementary times. This is probably the biggest loss of all as those things can't be replaced.