It's been more than a month since an American gunship destroyed a hospital run by Doctors Without Borders in Kunduz, Afghanistan. The attack left the area without a proper medical facility. Here is a look at the destruction. (Sudarsan Raghavan and Jason Aldag/The Washington Post)

The crew of an American gunship that attacked a hospital in Kunduz last month, killing 30, misidentified the target, confusing it with a building thought to be a Taliban stronghold several hundred yards away, a U.S. military investigation has concluded. The crew members were, as well, beset by “fatigue and a high operational tempo.”

“This was a tragic and avoidable accident caused primarily by human error,” Gen. John Campbell, the top U.S. commander for Afghanistan, said at a news conference in Kabul on Wednesday. But that human error, he said, was “compounded by systems and procedural failures.”

Several American personnel, most likely pilots and Special Operations members who made the decision that led to one of the deadliest incidents of civilian casualties in the war, have been suspended and could face further disciplinary action.

The location of the Doctors Without Borders Hospital was widely known in Kunduz. But the aircrew, hampered by a technical communications breakdown, mistook it for the headquarters of the Afghan security service, which Taliban fighters had reportedly seized when they briefly took control of the city and which was the intended target, Campbell said.

Faulty planning and procedures to approve airstrikes, as well as the absence of a single system to vet proposed targets against a no-strikes list, compounded the mistake, he said.

“The investigation found that some of the U.S. individuals involved did not follow the rules of engagement,” said Gen. Wilson Shoffner, the top U.S. military spokesman in Afghanistan.

Investigators also concluded that those who requested the airstrike, as well as those who executed it, did not verify that a legitimate military target was being hit, Campbell said. That raises a serious question about the extent to which the U.S. military can trust its Afghan partners: The coordinates and call for airstrikes started with the Afghans, Campbell and Shoffner said.

And other questions remain. Not long before the attack on the hospital, a U.S. airstrike pummeled an empty warehouse across the street from the Afghan intelligence headquarters. How U.S. personnel could have confused its location only a few hours later is not clear, nor is it clear why the gunship repeatedly struck the hospital when there was no return fire.

“The U.S. version of events presented today leaves MSF with more questions than answers,” said Christopher Stokes, the general director of the medical aid agency, also known by its French initials MSF, for Médecins Sans Frontières. “The frightening catalogue of errors outlined today illustrates gross negligence on the part of U.S. forces and violations of the rules of war. The destruction of a protected facility without verifying the target — in this case a functioning hospital full of medical staff and patients — cannot only be dismissed as individual human error or breaches of the U.S. rules of engagement.”

The group reiterated its call for an independent investigation.

According to the U.S. report, on the night of Oct. 2, Afghan special forces requested air support to help clear Taliban fighters from the headquarters of the intelligence service, known as the National Directorate of Security, or NDS. The U.S. Special Operations commander on the ground agreed, but he had no clear view of either the NDS building or the Doctors Without Borders hospital.

From this point on, errors occurred, Campbell said.

The powerful AC-130 gunship dispatched to provide air support flew out quickly without conducting a normal mission brief and without vital information, including the list of ­no-strike areas. And during the flight, the electronic systems malfunctioned, preventing the pilots from sending or receiving e-mail or electronic messages or transmitting video back to control rooms, Campbell said.

In addition, the aircrew thought the aircraft was targeted by a missile, which forced the gunship to move away from its original flight path, lessening the accuracy of some of its targeting systems, Campbell said. By the time the plane got the strike coordinates for the NDS building, they correlated to an open field 300 meters away from the NDS building (about 330 yards). So the aircrew decided to visually target the hospital, which was near the field and superficially matched the description of the NDS compound.

Still, the attack on the hospital could have been prevented, investigators found. The gunship, at one point, returned to its original flight path, and the grid location system correctly aligned with the NDS building. But “the crew remained fixated” on the hospital and did not rely on the grid location system, Campbell said.

Investigators also found that the aircrew did not observe any hostile activity coming from the hospital and therefore could have opted not to rake the compound with bursts of cannon fire.

The report found that the commander of the Special Operations forces lacked the authority to direct the aircrew to attack the hospital, Campbell said.

A minute before opening fire, the crew provided the coordinates of the hospital to the U.S. military’s operational headquarters. But personnel there did not realize that the coordinates matched a location on the no-strike list, Campbell said.

“We have learned from this terrible incident,” he said. “We will study what went wrong and take the right steps to prevent it in the future.”

Stokes, of Doctors Without Borders, was not convinced. “It is shocking that an attack can be carried out when U.S. forces have neither eyes on a target nor access to a no-strike list, and have malfunctioning communications systems,” he said. “It appears that 30 people were killed and hundreds of thousands of people are denied lifesaving care in Kunduz simply because the MSF hospital was the closest large building to an open field and ‘roughly matched’ a description of an intended target.”

Human Rights Watch also called for an independent investigation. “ ‘Mistakes,’ ‘errors,’ ‘processes,’ ‘circumstances’ — a lot of potentially accountability shedding verbiage, but the fact is that today’s explanations leave open serious questions about whether attackers knowingly or recklessly fired on a functioning hospital,” said John Sifton, Asia policy director at the organization.

Said Shoffner: “We believe the investigation completed was full and impartial.”

Read more:

Inside the Afghan hospital bombed by the U.S.

By evening, a hospital. By morning, a war zone.

The Pentagon’s evolving response to the Afghan hospital attack

Afghan response to hospital bombing is muted, even sympathetic