Kabul, Afghanistan (CNN) -- An investigation into an attack that killed eight U.S. troops in eastern Afghanistan last year said the combat outpost was an "attractive target" because protection improvements hadn't been made and intelligence assets had been diverted.
These were main points in the findings released Friday by the U.S. military into the probe of the October 3 attack on Combat Outpost Keating in the Kamdesh district of Nuristan province.
The attack killed eight U.S. service members and wounded 22 others.
Based on the recommendations in the investigation, Gen. Stanley A. McChrystal, the top coalition military commander in Afghanistan, "took appropriate action regarding Army personnel involved."
The report also praised soldiers of B Troop, 3rd Squadron, 61st Calvary for repelling the assault by a force of 300 militants.
Commanders must regularly assess "the value and vulnerabilities" of combat outposts, said the report, which "made several recommendations to improve coalition tactics."
The base had been scheduled to be closed before the attack occurred, and "needed force protection improvements (which) were not made" because of the imminent closure.
"Critical intelligence, surveillance and reconnaissance assets which had been supporting COP Keating had been diverted to assist ongoing intense combat operations in other areas," the report said. It also said "intelligence assessments had become desensitized to reports of massing enemy formations by previous reports that had proved false."
All of these factors "resulted in an attractive target for enemy fighters."
The military says militants had been planning the attack for days, hiding mortars, rockets and heavy machine guns in the mountains.
The assault started around dawn as bullets and rockets peppered the remote outpost October 3 and lasted for 12 hours, pinning down the exhausted troops.
One soldier said afterward the insurgency was so fierce that the troops couldn't get to their weapons to fire back. They called in air support to help thwart the militants.
"They were under heavy enemy contact," Sgt. Jayson Souter said.
Four servicemen -- Souter, a fellow soldier, an Apache helicopter pilot and a gunner -- talked to a military reporter about their roles during the Keating attack in an interview posted by the Department of Defense on Facebook and NATO's International Security Assistance Force YouTube Channel.
Chief Warrant Officer Ross Lewallen, an Apache pilot, said a few aircraft were damaged in what was a "time-consuming endeavor" governed by tough terrain. He said the morning battle was "significant," but later troops were able to identify targets and eliminate larger weapons.
"One of the primary reasons for the fight taking so long is that it is an extreme terrain," he said in the interview.
The report said the troops killed 150 enemy fighters and "found that the soldiers and junior leaders fought heroically in repelling an enemy force five times their size.
"Members of B Troop upheld the highest standards of warrior ethics and professionalism and distinguished themselves with conspicuous gallantry, courage, and bravery under the heavy enemy fire that surrounded them."