A midair collision between two firefighting helicopters battling a wildfire in Greece killed two crew members and left two others alive, authorities said. The two who died, a Greek coordinator and a Danish pilot, were aboard the same helicopter. The crews were attempting to extinguish a fire on the border of the Attica and Boeotia regions of Greece, around 40 miles west of Athens. Strong winds made it difficult for the more than 500 firefighters and nearly two dozen aircraft to control the blaze. Three other firefighters died last week in Greece while attempting to put out wildfires.