The U.S. attack on the hospital run by the NGO Medicins Sans Frontieres (MSF) in Kunduz, Afghanistan, during the night of October 2-3 was a “tragic but avoidable accident…the direct result of human error, compounded by systems and procedural failures,” according to Gen. John Campbell, commander of U.S. forces in Afghanistan. In a media briefing last week, Campbell said that an unspecified number of individuals had been suspended from duty and are facing disciplinary action. The attack, conducted by an Air Force AC-130 gunship, killed 30 staff and patients and injured 37.

Campbell summarized the results of an inquiry into the incident by three generals from outside his command. He said that after Taliban forces attacked Kunduz on September 27, MSF sent the coordinates of the hospital to multiple U.S. and NATO recipients. Five days later, after intensive fighting to regain control of the city, Afghan special forces requested U.S. close air support for their attempt to retake a security headquarters building from insurgents. This building was several hundred meters from the hospital.

The AC-130 crew took off from Bagram airbase more than an hour before schedule without conducting a normal mission brief, because they were responding to a troops-in-contact (TIC) incident elsewhere. They therefore did not have the MSF hospital identified as a “no-strike location.” The TIC incident was resolved without their help, and the AC-130 set course for Kunduz. En route, however, “the electronic systems onboard the aircraft malfunctioned, preventing the operation of an essential command and control capability and eliminating the ability of the aircraft to transmit video, send and receive e-mail or send and receive electronic messages,” according to Campbell.

As the AC-130 approached Kunduz, its crew believed they were targeted by a surface-to-air missile, and therefore chose to orbit eight miles from the target area, which was “several miles” more than usual. This degraded the accuracy of the EO/IR video sensor/targeting systems; the AC-130 is equipped with two or three sensor turrets, with some additionally carrying a synthetic aperture radar.

The U.S. special operations forces (SOF) commander directing the AC-130 attack from beyond visual range sent the correct coordinates for the security headquarters building to the AC-130 via his joint terminal attack controller (JTAC). But the aircraft’s sensors then slewed to an open field some 300 meters away. The aircrew then identified and fired on the nearest large building: the hospital. The SOF commander “lacked the authority to direct the aircrew to engage the facility,” according to the report as quoted by Campbell.

MSF called U.S. headquarters at Bagram to say they were under attack, 12 minutes after it began at 0208. It was another 17 minutes before the HQ and the SOF commander realized the fatal mistake, by which time the AC-130 had ceased firing.