WASHINGTON >> Multiple failures led up to the deadly Niger attack last October, but top military leaders said today that none directly caused the overwhelming enemy ambush that killed four American service members and sent others fighting and running for their lives.

“The direct cause of the enemy attack in Tongo Tongo is that the enemy achieved tactical surprise there and our forces were outnumbered approximately three-to-one,” Maj. Gen. Roger Cloutier Jr. told reporters during a Pentagon press conference.

He described a brutal, chaotic firefight, as 46 U.S. and Nigerien forces battled more than 100 enemy fighters. Amid the chaos, he said, there were repeated acts of bravery as the outnumbered and outgunned soldiers made split-second decisions under heavy fire, struggling to protect and rescue each other during the more than hourlong assault.

Killed in the attack were: Army Sgt. La David T. Johnson, 25, of Miami Gardens, Florida; Staff Sgt. Bryan C. Black, 35, of Puyallup, Washington; Staff Sgt. Jeremiah W. Johnson, 39, of Springboro, Ohio; and Staff Sgt. Dustin M. Wright, 29, of Lyons, Georgia. Four Nigerien troops were also killed, and two American soldiers and eight Nigerien forces were wounded.

The Americans who were killed “gave their last full measure of devotion to our country and died with honor while actively engaging the enemy,” the report said. None were captured alive by the enemy, and all died immediately or quickly from their wounds, it said.

After months of silence during the investigation, Gen. Thomas Waldhauser, head of U.S. Africa Command, laid out the findings and took responsibility for what happened.

He said the report, which has not yet been made public in full, singles out three individuals whose actions could be faulted. He did not name them. U.S. Special Operations Command will make any discipline decisions, as well as recommendations on awards for valor, Waldhauser said, adding he believes there will be awards for numerous acts of extraordinary bravery by the troops.

The investigation has already triggered changes in the way military activities are carried out in Niger and elsewhere in Africa, including giving teams the option to use heavily armored vehicles and beefed-up firepower.

“We are now far more prudent on our missions,” said Waldhauser, who sat alongside Cloutier, Africa Command’s chief of staff who led the investigation.

A report summary released today includes recommendations to improve mission planning and approval procedures, re-evaluate equipment and weapons requirements, and review training that U.S. commandos conduct with partner forces.

Defense Secretary Jim Mattis directed Waldhauser to take immediate steps to address shortfalls, and has given senior leaders four months to complete a review and lay out a plan for additional changes.

The summary lays out a confusing chain of events that unfolded on Oct. 3-4, ending in the ambush, and points to “individual, organizational, and institutional failures and deficiencies that contributed to the tragic events.” But it concludes that “no single failure or deficiency was the sole reason” for what happened.

It said the U.S. forces didn’t have time to train together before they deployed and did not do preparatory battle drills with their Nigerien partners. And the report said lax communication and poor attention to details led to a “general lack of situational awareness and command oversight at every echelon.”

Robert Karem, the assistant defense secretary for international security affairs, who also spoke, said there are about 800 U.S. troops in Niger, and that none are supposed to be engaged in direct combat. Most are involved in the construction of a new air base there.

According to the report, the Army Special Forces team left Camp Ouallam on Oct. 3 to go after Doundou Chefou, a leader of the Islamic State group who was suspected of involvement in the kidnapping of an American aid worker. But the team leader and his immediate supervisor submitted a different mission to their higher command, saying they were simply going out to meet tribal leaders.

Waldhauser called the mischaracterization of the mission unacceptable, but Cloutier rejected suggestions the team leaders lied. It’s not clear if those two are among the three service members he said could face discipline.

“It wasn’t a deliberate intent to deceive,” Cloutier said. “It was lack of attention to detail.”

When the Ouallam team got to the location the insurgent wasn’t there.

Senior commanders, unaware of the team’s earlier actions, then ordered the troops to serve as backup for a second team’s raid, also targeting Chefou. That mission was aborted when weather grounded the second team. The Ouallam team members were then ordered to another location to collect intelligence also linked to Chefou, which they did without problems. On their way back to their home base they stopped at the village of Tongo Tongo to get water.

Soon after leaving Tongo Tongo, about 120 miles (200 kilometers) north of Niamey, Niger’s capital, they were ambushed by Islamic State-linked militants carrying small arms and machine guns.

The report concludes that although the enemy fighters can move freely around the village area, “there is not enough evidence to conclude that the villagers of Tongo Tongo willingly (without duress) aid and support them. Additionally, there is insufficient evidence to determine if villagers aided the enemy or participated in the attack.”

Cloutier said it appears insurgents attempted to take away the bodies of three of the killed American troops — Black, Wright and Jeremiah Johnson — but fled when French fighter jets buzzed the area. Two of the bodies were found in the bed of an enemy truck, and another was beside it.

The other American fatality, La David Johnson, and two Nigerien soldiers got separated from the others during the battle and were gunned down. Johnson’s body wasn’t found until two days later. All were stripped of weapons and equipment.

Families of the fallen have expressed frustration with the incident and the briefings they got.

“The whole thing was a screwed-up mess,” said Arnold Wright, father of Staff Sgt. Dustin Wright of Lyons, Georgia, who was killed in the attack. Wright said he’s concerned the Army may be pinning blame on lower-ranking soldiers and not accepting responsibility high enough up the chain of command.