The planes from that airport need to climb high fast soon after takeoff in order to avoid ground fire by Taliban.
Note the unusually steep angle of the plane from the video.
Possible reasons
• Too steep a climb so soon after takeoff
• Overloading
• Restraining devices give way and armoured cars move inside plane
• Wrong CG
• Plane got engine problems
• Suicide intruder hiding in plane killed the pilots.
Today there was another US military transport C-135 plane reported crashed after taking off from Kyrgyzstan.
This may be a new pattern of attack on US military transport planes.