WASHINGTON – Dramatic new drone video of the Niger ambush that killed four American soldiers shows U.S. forces desperately trying to escape and fighting for their lives after friendly Nigerien forces mistook them for the enemy. It describes how the fleeing troops set up a quick defensive location on the edge of a swamp and -- thinking they were soon to die -- wrote messages home to their loved ones. The video, released by the Pentagon with explanatory narration, includes more than 10 minutes of drone footage, file tape and animation that wasn't made public last week when the military released a portion of the final report on the October attack. The video depicts for the first time the harrowing hours as troops held off their enemy and waited for rescue. There were 46 U.S. and Nigerien troops out on the initial mission in the west African nation, going after but failing to find a high-value militant, then collecting intelligence at a site where the insurgent had been.