KABUL, Afghanistan — The American airstrike that destroyed a Doctors Without Borders hospital in Kunduz last month was the result of human errors, failures in procedure and technical malfunctions, according to military officials briefed on the internal investigation.

“It’s a combination of factors,” said a senior Defense Department official, describing the findings in a 3,000-page investigative file examining the Oct. 3 airstrike that killed at least 30 people, mostly doctors and patients. The military is expected to give details on the findings at a news conference on Wednesday.

Two other military officials briefed on the investigation said the Special Operations AC-130 gunship used was intended to target a different compound several hundred feet away that was thought to be a Taliban base of operations in the city.

The military officials, who spoke on the condition of anonymity to discuss the report before its official release, said the investigation found that the gunship’s crew had been unable to rely on instruments to find the target. Instead, they relied on descriptions of the location relayed by troops on the ground, a mix of American and Afghan Special Forces. Based on those descriptions, the crew locked onto the hospital compound, mistakenly believing that it was the building the ground troops were describing, the two officials said.