An 18-year-old Missoula woman died in a scuba diving accident in Glacier National Park’s Lake McDonald Sunday.

The accident happened in the waters off the dock from the Lake McDonald Lodge, the Park said in a release. The cause of the accident is still under investigation and the woman’s name has not been released.

The deceased was part of a scuba diving group of six people that started its dive near the dock of Lake McDonald Lodge around 4 p.m. 

Efforts to revive the woman by members of the dive team and by emergency personnel were unsuccessful.

At the time of the incident, by-standers drove to Apgar Village for cell signal to call 911. The ALERT helicopter was first on the scene, about 30 minutes after the initial 911 call. A second diver, a 22-year-old male, suffered shortness of breath and was transported by Three Rivers Ambulance to Kalispell Regional Medical Center. He was later flown to Seattle, Washington for hyperbaric treatment.

Lake McDonald is popular among some scuba diving groups because of submerged artifacts. Permits are not required to dive in Glacier and diving equipment is not subject to Aquatic Invasive Species inspections.

The lake drops off quickly at the dock. At its deepest point, the lake is about 464 feet deep.