The Pentagon will report what really happened to 4 soldiers in Niger

The Pentagon is releasing a redacted version of the lengthy Niger ambush investigation that is expected to focus on the command and tactical decisions that led to the deaths of four members of the Army's Third Special Forces Group.

Defense Secretary Jim Mattis has said the Article 15-6 fact-finding investigation is thousands of pages long. Pentagon officials said the report would include an animated video of what happened on the joint patrol with Nigerien troops near the village of Tongo Tongo in northwestern Niger on Oct. 4, 2018.

The families of the fallen and members of Congress have already been briefed on the findings, which were expected to answer the lingering questions about how a patrol of 12 U.S. and approximately 30 Nigerien troops came to be overwhelmed by fighters from an offshoot of the Islamic State of Iraq and Syria.

In a briefing shortly after the ambush, Joint Chiefs Chairman Gen. Joseph Dunford said the mission had been expected to pose little risk.

However, the mission reportedly was changed and sent the patrol after a high-value militant linked to the offshoot called ISIS in the Greater Sahel.

Those killed in the patrol were Sgt. La David 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 and a Nigerien interpreter also were killed in the ambush near the Mali border as the patrol was returning to base near the Nigerien capital of Niamey.

Black's father has declined to fault the decisions that led to the ambush.

He told National Public Radio, "I would not personally characterize them as mistakes. They were just decisions based on what they knew, and I believe that those decisions were sound decisions."

One of the questions that is expected to be answered is how Sgt. La David Johnson came to be separated from the rest of the patrol during the ambush. His body was not found until two days after the attack.

The noontime briefing at the Pentagon on the investigation is expected to be led by Assistant Secretary of Defense for International Security Affairs Robert S. Karem and Marine Gen. Thomas D. Waldhauser, commander of U.S. Africa Command.

Waldhauser's chief of staff, Army Maj. Gen. Roger L. Cloutier, who led the Article 15-6 investigation, is also expected to join the briefing.

This article originally appeared on Military.com. Follow @military.com on Twitter.