The National Park Service announced late Monday that an 18-year-old woman died Sunday while scuba diving in a lake at Glacier National Park in Montana. A second diver, a 22-year-old male, suffered from decompression sickness and was flown to Seattle for treatment. The pair were part of a group of six who were diving at Lake McDonald near its eponymous lodge. The NPS hasn’t said what caused the death at the 500-feet deep lake, but it’s under investigation. The divers have not been identified.