ABC7 learned the incident happened on Monday afternoon, between 5 and 6 p.m. in a high security section, surrounded by fencing and razor wire. It is an area where people found incompetent to stand trial are housed.
According to the sheriff's department, 47-year-old William Roebling was subdued after he allegedly attacked another patient. The staff performed CPR, but Roebling died at the hospital and now staff members are worried what other patients might do.
"There's some individuals, some of the patients, who are now threatening other staff because one of the patients died. And patients and staff are both really worried. They're scared. They're scared that something else is going to happen," said Kathleen Thomas-Morris, a SEIU steward.
Tuesday St. Sen. Noreen Evans and Assm. Michael Allen sent a letter to the governor saying "Quite simply, this ongoing situation in our state hospitals is unacceptable -- and deadly. More than 80 percent of those being treated at state hospitals arrive... through the criminal justice system. It is time we have laws, regulations, and on-site practices employed that reflect this new reality."
Earlier this year employees held several protests demanding more peace officers, a campus-wide alert system and more staffing. That followed the killing six months ago of a psychiatric technician who was attacked by a patient, another patient attacked a therapist in December, and now this incident on Monday.
It's unclear how the patient died. An autopsy is scheduled for Wednesday.
ABC7 attempted to reach the hospital for comment and were told to call back in the morning.
