CASPER, Wyo. (AP) — Authorities say a Rock Springs teen died of hypothermia after crashing his car and trying to get to shelter last month.

The Casper Star-Tribune (http://bit.ly/xMv0vd ) reports Sweetwater County Coroner Dale Majhanovich determined that 18-year-old Vernon Johnson did not die from wounds sustained in the Dec. 30 crash, nor was alcohol involved.

The sheriff's office says Johnson was headed to see the city lights from White Mountain with two 17-year-old girls when he crashed. The three tried to walk out of the area and ended up sleeping in a draw by the side of the road. In the morning, the girls tried to help Johnson stand, but he collapsed and died.