21.   A preliminary report by the Air Transportation Office said pilot error may have caused the crash, but did not clear the airline of negligence.

22.   A preliminary report by the Air Transportation Office said pilot error may have caused the crash, but it did not clear the airline of negligence.

23.   A preliminary report by the Air Transportation Office said that pilot error may have caused the crash, but it did not clear the airline of negligence.

24.   A preliminary report by the ATO said pilot error may have caused the crash, but it did not clear the airline of negligence.

25.   An earlier inquiry concluded pilot error caused the Russian-made Tupelov plane to crash into a hill in eastern South Africa.

26.   Crash investigators have not formally concluded that pilot error caused the accident.

27.   Dortmund prosecutor Karl-Dieter Staat said that after speaking with the survivor, he is investigating whether pilot error may have caused the accident.

28.   Energy and Mineral Affairs Minister Pik Botha said it appeared human error caused the accident because the locomotive went through a safety barrier and fell into the shaft.

29.   Energy and Mineral Affairs Minister Pik Botha said it appeared human error caused the accident.

30.   Federal investigators have concluded pilot error caused the plane crash that killed John F. Kennedy Jr., his wife and his sister-in-law, NBC News reported Thursday.