UPDATE: Three men arrested in connection with death of woman at Oceano Dunes

Three men have been arrested on suspicion of involuntary manslaughter after they allegedly buried an unconscious woman in sand at the Oceano Dunes, which caused her death.

Rangers were called to a campground near Beach Post 4 at the dunes at 7:20 p.m. Wednesday. When they got there, they saw people administering CPR to Patricia Ann Kalbskopf, 53. She was rushed to Arroyo Grande Community Hospital, where she died on arrival.

Kalbskopf had allegedly been drinking and passed out, according to sheriff's investigators. The three men she was with then piled sand on her, and later noticed she was not breathing.

An autopsy performed Thursday showed Kalbskopf died of asphyxiation from inhaling sand.

The three men arrested in connection with the death are as follows:

James Lee Proffer, 52, an unemployed transient;

David Wesley Cartwright, 59, an unemployed transient and a parolee at large from Southern California;

Kelly Marvin Johnson, 41, a retired carpenter who lives on Perfumo Canyon Road in San Luis Obispo.

The three were initially arrested for allegedly being drunk in public and arrest warrants.

-Larissa Doust