Two planes crash mid-air during Dallas air show

Two historic military planes collided and crashed to the ground Saturday during an air show in Dallas, exploding into a ball of flames and sending plumes of black smoke billowing into the sky. It was not clear how many people were on board the planes.Emergency crews raced to the crash scene at the Dallas Executive Airport, about 10 miles (16 kilometers) from the city’s downtown.News footage from the scene showed crumpled wreckage of the planes in a grassy area, apparently inside the airport perimeter.