army mechanic, got separated from the 11 other u.s. troops. un's also unknown whether he was alive when the wounded troops were evacuated. his body was recovered two days later. on the morning of october 4th, the soldiers were on a joint patrol with 30 nigerian earces near the village of tongo tongo where they had just met with elders and loaded up with supplies. they were at the end of a 24-hour mission when the attack began, an hour into the fight, the patrol called for help, and french forces arrived 30 minutes later. the military soon declared a dust one or duty status whereabouts unknown for sergeant johnson. a request was made the chairman of the joint chiefs, joseph dunford, for more u.s. personnel. u.s. commandos based in the sgion were launched. >> at that point, knowing that we had a missing soldier, we made a decision to make sure that all of the resources including national assets were available for the recovery of that operation. >> reporter: it is still unclear eaether the attack was pre- planned, but investigators nelieve it was carried out by an isis offshoot operating in the area.