Authorities are investigating the drowning of a 34-year-old man in St. Pete Beach.

Deputies with the Pinellas County Sheriff's Department say Bret Alexander Rule was last seen on Sunday, alone on the beach. Witness say he appeared to be intoxicated and was acting incoherently.

According to the Patrol Operations Bureau, Rule entered the water between 5 p.m. and 6:30 p.m. and did not return.

A passerby found Rule unconscious and pulled him out of the water behind the Plaza Beach Motel on Gulf Blvd.

St. Pete Beach Fire Department paramedics arrived on scene and attempted life-saving measures until Rule was transported to Palms of Pasadena Hospital where he was later pronounced deceased.

Deputies say that alcohol or drugs do appear to be factors in Rule's death and the investigation is ongoing.