BROWNSVILLE, Texas (ValleyCentral) — The Cameron County Sheriff’s Office released the name of a woman was found unresponsive in her jail cell last month.

Sylvia Manuel, 63, was pronounced dead July 25 after she was found on the floor unconscious in a single cell at Carrizalez-Rucker Cameron County Detention Center.

A preliminary autopsy report indicates Manuel died of a ruptured myocardial infarction, commonly known as a heart attack.

Manuel’s death is ruled as a natural cause, CCSO stated.

Texas Ranger Patrick O’Conner processed the scene and took lead in the investigation.