Chain of Command Clip: Sgt. La David Johnson Watch a clip from National Geographic's "Chain of Command" docu-series featuring Sgt. La David Johnson from the 3rd Special Forces Group. In a scene from National Geographic’s documentary series “Chain of Command,” Sgt. La David Johnson, one of four soldiers killed in the October ambush in Tongo Tongo, Niger, is shown speaking with a fellow soldier while moonlighting as a barber on base. “For team mechanic La David Johnson, staying busy often means wearing multiple hats,” actor Chris Evans, who narrates the documentary, says as Johnson is shown buzzing the hair of another soldier. “When you’re not cutting hair, what are your other camp duties around here?” Johnson is asked in the episode that first aired Monday night. It will air again at midnight Eastern time Wednesday. “Finding stuff to do, like making sure my truck is good, making sure my generator is good. Like regular maintenance on the daily,” Johnson responds. “A jack of all trades. Where did you learn to cut hair?” he’s asked. “Uh, YouTube,” Johnson says. “Yes, sir. YouTube. [I’d] watch videos, just sit here and just cut my own hair. Keep it in regulations.” “What’s one training you don’t have right now that you wish you had already on this trip?” the fellow soldier asks. “Is there something you haven’t been able to fix or do that you’ve been asked to do on this trip?” “Negative, sir. Not yet,” Johnson responds with a smile. Staff Sgt. Bryan Black, from left, Staff Sgt. Jeremiah Johnson, Sgt. La David Johnson and Staff Sgt. Dustin Wright were killed when a joint patrol of American and Nigerien forces was ambushed on Oct. 4, in Niger by militants believed linked to the Islamic State group. (Army) On Oct. 4, Johnson was part of the Special Forces element that was ambushed along Niger’s border with Mali. Four Americans and five Nigeriens were killed near a remote village during an intense gunfight in which U.S. forces never received air support. The region, which frequently hosts clashes between French forces and militants in Mali, is flush with activity by groups associated with the Islamic State and al-Qaida. A military investigation into the ambush was supposed to be released by January, but new reports indicate the investigation will be released sometime in March. According to the New York Times’ sources, the investigation is complete and circulating among Pentagon officials. However, the public release is being delayed until after the soldiers’ families and Congress are notified.