Transcript for New details on deaths of 4 US soldiers in Niger

Next, our team on the ground in Niger with new reporting on what happened to American special ops soldiers. The vehicle losing contact and is there a military offensive now in the works? Ian Pannell from Niger tonight. Reporter: Tonight, new details emerging about the timeline that saw four American soldiers ruthlessly gunned down here in Niger. Late today a senior intelligence official tells us a convoy of three trucks were fleeing the ambush. Two made it out of the kill zone. The third was cut off from the other vehicles, unable to communicate with the group, staff sergeants black, Johnson, and Wright in this vehicle. Soldiers then turned back to rescue them. Sergeant la David Johnson laying down gun fire in the desperate rescue. An official says the stranded vehicle was hit with mortar and gunfire, killing the 3 soldiers. Two hours into the battle, French jets arrived, flying low, scattering the attackers, preventing more fatalities, survivors then evacuating on helicopters. Back at the white house president trump, speaking about the mission for the first time this week, was asked if he authorized it. I didn't. Not specifically. I give them authority to do what's right so we win. Reporter: But tonight many questions remain, including how and why was sergeant la David Johnson was left behind, his body recovered two days later. You're hearing a major military offensive could be in the works to hunt down those responsible? We're hearing from the general who will lead this operation combining five separate countries in this region and they're going to try to find those responsible and those responsible for other terrorist attacks in the neighborhood. Perhaps they have got leads on who was responsible for ordering that attack. David. Back here at home a new fallout amid the discussion over

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