"Friends said that they woke up and found him unresponsive, cold to the touch," said Peters. "Unfortunately he wasn't able to be revived."
Armstrong is the son of two longtime Anchorage School District teachers. He had just wrapped up his junior year at Chugiak High School.
"It's just always such a tragedy, when you've got young people in the prime of their life and things happen, and now he's gone and I'm just feeling so sad for the parents," said Carol Comeau, Anchorage School District Superintendent.
Troopers say that Armstrong's death is a reminder that people need to be safe, and smart when recreating.