In the parlance of health officials, patient Mario Vidaurre's death was a "preventable occurrence."

On a summer day in 2007, a mental health technician at PSI's West Oaks Hospital in Houston went with Vidaurre, 41, into a courtyard for a smoking break. The technician, Fred W. Williams, was assigned to monitor him on his own, although the schizophrenic man, a former Golden Gloves boxer, had choked and torn the shirt of another staffer only days earlier.

As Williams leaned forward to light Vidaurre's cigarette, the patient slugged him in the face, according to Williams's subsequent statement to Houston police.

Isolated and unable to summon help, Williams, 35, said he grabbed the patient and took him to the ground. Vidaurre broke free. He rammed Williams' head into a wall.

Williams gained the upper hand and restrained Vidaurre until he grew still. Then he opened the door to the courtyard and shouted for help, federal inspection records say.

Within hours, Vidaurre was pronounced dead and Williams was being questioned by homicide detectives. A grand jury eventually declined to charge Williams in the incident.

Williams said that he had never been trained to deal with a combative patient on his own, according to his sworn testimony in a wrongful death lawsuit filed by Vidaurre's brother against the worker and the hospital.

"As far as violence, that always required either two or more techs, not one to one," Williams said.

The lawsuit is pending. West Oaks has filed a general denial in court papers. Williams' attorney has alleged that hospital, not the worker, was grossly negligent.

In a report, inspectors for the U.S. Centers for Medicaid and Medicare Services faulted the facility for, among other things, failing to assign two workers to monitor Vidaurre, per the hospital's own policy.

Krista Kjellman, Video Producer / ProPublica