Apparently, the Army base that started this mess got the situation under control, and David sees this all too clearly when soldiers start to clean up the area around him.
Unfortunately for David, there were five people and four bullets, leaving himself unable to finish his task by killing himself.
So he walks outside, egging on fate to engage in what we’ve come to know is the standard operating procedure of The Mist: the prospect of a horrific monster eating him.
But the real kicker is when he sees truckloads of survivors from the supermarket they had fled, including a woman who previously wandered into the mist, played by The Walking Dead’s Melissa McBride.