The U.S. Air Force reported that it had lost a MQ-9 Reaper UAV over western Afghanistan on September 13th. What it didn't report, at the time, was that the Reaper was shot down by a U.S. fighter. That was because something went wrong with the Reapers commo link, and the operator lost control of the aircraft. As air force techs scrambled to regain control, the Reaper continued to fly north, and this would eventually take the UAV outside of Afghanistan. The air force would not elaborate, but this could mean the aircraft would fly into Tajikistan, or China. It was thought prudent to ensure that the Reaper did not leave Afghanistan. Don't go all Skynet on us.
So a U.S. fighter was directed to catch up with it. A 4.6 ton Reaper cruises at about 300 kilometers an hour. Most jet fighters can easily do five or six times that, long enough to catch up. The air force did not say how the Predator was brought down (by cannon or missile, or by being tipped over by the backwash of a jet fighter passing very close). All the air force would say was that the Reaper crashed into an Afghan mountainside, far from any populated area, at about 5:30 AM, local time. The Reaper got reaped.
You'd think it would be programmed to just go to its home location and land if it lost contact. Then again, this is a government job, so I'm not surprised.