Deise Moura dos Anjos was found without vital signs during a morning check at a women’s state prison in the southern Brazilian city of Guaíba, in the state of Rio Grande do Sul, CNN affiliate CNN Brasil reported Thursday, citing local police. “Immediately, the staff provided first aid” and called the emergency medical service, “which, upon arriving at the scene, confirmed her death,” the criminal police said in a statement. “Deise was alone in the cell. The circumstances will be investigated by the Civil Police and the General Institute of Expertise,” the statement added. CNN Brasil reported that Dos Anjos’ husband, Diego, asked for a divorce the day before her death. The cake poisoning, which killed three people and hospitalized three others, occurred on Christmas Eve in the city of Torres in Rio Grande do Sul.