Tankers evacuate

A KC-135 Stratotanker takes flight during an evacuation May 18, 2017, at McConnell Air Force Base, Kan. The evacuation was completed to keep the aircraft out of the way of potential severe weather. (U.S. Air Force photo/Senior Airman Tara Fadenrecht)

A KC-135 Stratotanker takes flight during an evacuation May 18, 2017, at McConnell Air Force Base, Kan. The evacuation was completed to keep the aircraft out of the way of potential severe weather. (U.S. Air Force photo/Senior Airman Tara Fadenrecht)

A KC-135 Stratotanker takes flight during an evacuation May 18, 2017, at McConnell Air Force Base, Kan. The evacuation was completed to keep the aircraft out of the way of potential severe weather. (U.S. Air Force photo/Senior Airman Tara Fadenrecht)

A KC-135 Stratotanker takes flight during an evacuation May 18, 2017, at McConnell Air Force Base, Kan. The evacuation was completed to keep the aircraft out of the way of potential severe weather. (U.S. Air Force photo/Senior Airman Tara Fadenrecht)

Storm clouds roll in over an empty flightline at McConnell Air Force Base, Kan., May 18, 2017. Base leadership made the decision to evacuate aircraft to keep the assets out of the way of potential severe weather. (U.S. Air Force photo/Senior Airman Tara Fadenrecht)