A couple of years ago a plane with 48 passengers on board crashed, apparently without any reason. The plane had not reported any problems, the weather was good and after the crash there were no signs that an explosion of any kind occured during the flight. Investigators were puzzled, till they listened to the recordings of the voice recorder. When they played the black box recordings, the last words from the pilot were: "I wonder what happens when I push this button." Although the investigators searched for over a year, they never found out which button the pilot had pushed.