Fellow warriors of four Americans killed in an ambush shown mourning the loss of their heroic comrades.

Four Nigerien soldiers also were killed during the ambush.

It was a tragic incident that demanded answers to questions from the families of those killed, from Congress, and also from military commanders to find ways to prevent such occurrences in the future.

The U.S. military is a learning and growing organization. Finding out what happens when tragedies or accidents occur is a priority for the Defense Department and the combatant commanders, Pentagon officials said, and the results can also affect interagency and international partners.

The commands and services need to know what happened, and whether something systemic can be done to improve policies, regulations, tactics, techniques and procedures, officials explained.

Lessons of Engagement

Commanders need to learn the lessons of the engagement. They need to understand what happened, when, and what the results were. They need an impartial set of eyes to examine the evidence and draw conclusions.

The military has such a system. The incident in Niger is one prominent example of this methodical examination of evidence, but there are more. For example, the Navy investigated the June collision of the USS Fitzgerald with a civilian ship off the coast of Japan last year, and investigated the collision of the USS McCain with a civilian ship in August off the coast of Singapore. A total of 17 sailors died in the incidents.

The military also investigated an October 2015 AC-130 Spectre gunship airstrike in Kunduz, Afghanistan, that mistakenly hit a Doctors Without Borders medical facility. The United States made more than 170 condolence payments to the families of those hurt or killed in the strike.

For the Niger incident, Marine Corps Gen. Thomas D. Waldhauser, the commander of U.S. Africa Command, appointed Army Maj. Gen. Roger L. Cloutier Jr., the Africom chief of staff, to conduct the investigation under Army Regulation 15-6.

This is in line with the ethos and culture of the military, officials said, noting that typically, personnel look at every operation, mission, exercise, system and process to glean lessons learned and apply them.

When a squad conducts an operation outside the wire in Afghanistan, for example, the soldiers, Marines or special operators gather to go over the movement to see what they could have done better. After F-22 Raptors return from a mission, the pilots are debriefed with everyone looking for ways to better accomplish similar missions in the future.

When a ship returns from a deployment, the officers and senior noncommissioned officers examine ways to make future deployments more effective.

And when something goes terribly wrong, the need for this information becomes even more acute.

An Army Regulation 15-6 investigation is a process used at multiple levels of command. The incident in Niger led to an informal investigation, and Cloutier had a staff and lawyers to advise him in conducting the investigation. The process is designed to gain understanding of what happened via interviews with all available witnesses, imagery, reports, physical presence at the scene of the events and much more. Each service and the Defense Department has a similar process to get at the truth and to make recommendations.

Getting It Right

It is far more important to get it right than to get it quickly. “We want to have that investigation concluded as quickly as possible, but we have prioritized making sure that the investigation is accurate,” Marine Corps Gen. Joe Dunford, the chairman of the Joint Chiefs of Staff, said when he briefed Pentagon reporters on the incident in Niger on Oct. 23. “And that when we go to the families and we tell them what happened, that it’s based on facts. So we’re trying to balance the need to do this quickly with the need to make sure that it’s accurate. And I think we will certainly err on the side of accuracy.”

As a comparison, the investigation into a recent engine malfunction aboard a Southwest Airlines jet is expected to take a year.

The Niger investigation is complicated because the operation involved many factors. The soldiers were on a partnered mission with a Nigerien force when the ambush occurred. They received intelligence and information about the mission from a variety of sources. French forces were involved as air support and for casualty evacuation, along with U.S. military contracted resources. Nigerien forces also responded as the quick-reaction force. The event had many moving parts from three continents involved.

Complicated Investigation

Gathering the information and evidence for the investigation also is complicated. It must be collected methodically to verify actions during the events and to ensure the evidence is factual to draw the correct conclusions. On the American side alone, investigators spoke with personnel at Fort Bragg, North Carolina, at Walter Reed National Military Medical Center in Maryland, in Niger and in Europe.

Interviews with French forces ranged from took place in Niamey, Niger, and in Paris. Interviews with Nigerien soldiers were conducted in Niamey and at other bases in Niger. On Nov. 12, Cloutier led the investigation team to the scene of the firefight near Tongo Tongo and spoke with villagers and with Nigerien military forces there.

Investigators then had to assess the evidence collected and begin building the timeline, matching oral presentations next to digital and physical evidence. All of this is done with the understanding that the investigation must be thorough, based on evidence and unbiased. Still, the fog of war means there will always be aspects that are unknowable.

The investigation report is a comprehensive look at the actions and the conclusions that can be drawn from it. Before Cloutier submitted it to the Africom commander, he submitted it to legal and security experts for review.

After Waldhauser’s endorsement, the report’s complexity required further review by Dunford and Defense Secretary James N. Mattis.

The families of the four soldiers and congressional committees were briefed before today’s release of the investigation report.

(Follow Jim Garamone on Twitter: @GaramoneDoDNews)