A Petaluma teen who was found dead Jan. 4 in South Lake Tahoe likely succumbed to hypothermia after she ingested large amounts of methamphetamine and other illegal drugs and wandered away from a music festival, authorities said Monday.
Alyssa Byrne, 19, disappeared after she attended a New Year's Eve concert at Lake Tahoe Community College. A utility worker discovered her body three days later about a half-mile away near a snowbank.
The El Dorado County Sheriff's Office released results of an autopsy Monday revealing that the Casa Grande High School grad probably froze to death.
The amount of methamphetamine found in Byrne's system was enough to be considered toxic and also contributed to her death, sheriff's Lt. Pete Van Arnum said Monday.
He said the drug "could have possibly killed her if she hadn't frozen to death first."