General Joseph Votel said that on October 3, 2015, the crew of an AC-130 gunship had taken off earlier than planned without a list of protected sites and had been mistakenly guided to bombard the Kunduz trauma center.
The general, head of US Central Command, said that 12 of the personnel involved -- commanders, flight crew and a special forces team on the ground -- had been suspended or removed from command and four others were reprimanded.
"The investigation found that the incident resulted from a combination of human errors, process errors and equipment failures and that none of the personnel knew they were striking a hospital."
Votel said that a US special forces group accompanying Afghan forces had called for air support after four days of heavy fighting against the Taliban guerrillas who had overrun the northern city.
"Our forces did not receive fire from the trauma center during the incident nor did the investigation find that insurgents were using it as a base for operations," he said.
"Some insurgents were treated at the trauma center, but hospitals and patients are protected on the battlefield. The trauma center was a protected facility, but it was misidentified during this engagement.