In July 1993, five teenage boys and three men on an LDS youth group attempted a canyoneering trip in Kolob Creek of Zion National Park. The upstream Kolob Reservoir was releasing a ton per second of water through the canyon. Though this flow surprised them at the canyon's entrance, the leader believed that the park's rangers had assured them that their trip was safe, so they continued. Two of the adult leaders quickly drowned; the remaining man and five boys were trapped in the canyon for five days until the Park Service rescued them.