“PASSENGER PIGEONS” Dir.: Martha Stephens, 106 min. Poignant in the shadow of the recent West Virginia coal mine deaths, “Passenger Pigeons” interweaves four different stories surrounding an accidental death of a young man in an Appalachian mine: his brother, driving cross-country for the burial; two coal company executives, sent to inspect the mine, who end up camping in the woods; a young, concerned couple on vacation during the closure, and activists from Washington, D.C., in town to protest a mountaintop removal.