Airline glitches. The top cause of flight delays, according to a USA Today analysis.[6] Congestion in air traffic[6] Earthquakes and tsunamis (e.g., in the event of 2004 Indian Ocean earthquake and tsunami, 2010 Chile earthquake, and the 2011 Tōhoku earthquake and tsunami) Fueling[7] Inclement weather, such as thunderstorm, hurricane, or blizzard[7] Late arrival of the aircraft to be used for the flight from a previous flight[7] Maintenance problems with the aircraft[7] Security issues[7] Terrorist attacks (e.g., suicide bombing in the event of Domodedovo International Airport bombing, the 2016 Brussels bombings, and the 2016 Atatürk Airport attack)