A 19-year-old man reportedly drowned in St. Mary’s Lake over the holiday weekend after failing to resurface following a dive on Saturday. St. Mary’s Lake is found just below a glacier along the popular St. Mary’s Glacier hiking trail near Idaho Springs.

The man’s body was later pulled from the water after what one report estimates to have been an hour of searching. The teen was transported to a Denver-area hospital and pronounced dead.

According to local authorities, the water was cold at the time of the accident and boulders are present beneath the surface. Cold water can result in cold water shock, a condition that can impact one’s breathing and ability to move. This contributes to a number of drowning deaths in Colorado, as victims are unable to stay above the water when cold water shock sets in. It is unclear if this unidentified drowning victim suffered cold water shock.

The Saint Mary’s Glacier trail that travels past the lake is a popular 1.9-mile out-and-back route. It takes hikers to one of the state’s last remaining “glaciers,” with the namesake lake located just below the final climb. The glacier starts at around 10,400 feet above sea level, stretching to an elevation of more than 10,800 feet.