On our last trip, we were staying in Pop, it was our last day so we went down for breakfast while planning our last few hours before the ME. One second I'm checking the menu, the next we're trying to figure out where our 2 yr old went. Dh and I quickly looked around, didn't see her and didn't hear her, so I alerted a CM.
I was terrified she'd walked out the automatic doors toward the pool. I searched there a dozen times, but the pool was all clear. I don't know how long we searched for, but it felt like forever.
She didn't want to go home, she wanted to go see Mickey again. She knew how things worked, so she walked right out the automatic doors, and went straight for the first bus she found (ME). She was walking beside a family so never once looked out of place - and she was happy as could be.
The entire resort seemed to shut down while they searched for her. No busses moved and We saw security and managers popping out of the wood work. In the end the first CM I talked to was the one who found her - based on our description. She approached the other family and asked if she belonged to them. The CM then took her hand to lead her back to us - and THAT was when she started to cry
Not Disney, but amusing case of abandoned bag - when in University a friend was hauling a load of bricks in his back pack (I don't recall why he had them), they were heavy and he didn't want to lug them everywhere so he set them down in one building while he went for lunch. in the mean time, the building was locked down, the SWAT team arrived as did the bomb dogs. It was scary to have everyone come piling into where we were eating telling about the bomb - upon having the bag described, my friend realized what was happening and ran over to retrieve his bricks. He arrived just as the bag was deemed safe and the police opened it.

Poor guy will never live it down.