The Air Force says a series of system malfunctions caused one of its drones to crash into Lake Ontario in November.
The Air Force released its investigation into the MQ-9 Reaper crash on Tuesday.
The crash occurred about 35 miles southwest of Fort Drum, New York, during training. The report says there were multiple failures with the drone's GPS and inertial guidance system, among other things.
The drone and its aircrew were assigned to the 174th Attack Wing at Hancock Field Air National Guard Base, New York.
The drone was valued at about $10.6 million and was destroyed on impact. Pieces of the drone later washed ashore about 12 miles east of where it crashed.
The investigation was conducted by a board at Langley Air Force Base in Virginia.