A 5-year-old Maryland boy died when a wind gust sent a bouncy house 15 to 20 feet in the air on Friday night. Charles County authorities said it happened about 9:20 p.m. during a Maryland Blue Crabs baseball game at Regency Furniture Stadium. Officials said children fell before the inflatable landed on the playing field. Charles County EMS personnel, who were already stationed at the stadium for the game, along with trainers from the baseball team and several volunteer first responders immediately began to treat the young victims. Maryland state police rushed the worst injured victim to Childr…