ST. LOUIS – Another St. Louis jail death brings a response from a special police investigation unit.

This is the second reported death at the St. Louis Justice Center in less than two weeks. As families went to visit their loved ones this morning, they were alarmed to learn about this latest incident.

“Is it my son?” Natalie Springfield said. “Because I haven’t spoken to him. Saturday will be two weeks.”

Springfield says it scares her that she has no way of finding out and that she was just turned away for a visit.

“They won’t let me in to see him,” she said. “I can’t speak to him. I can’t visually see him, and for all I know, he may not even exist anymore.”

An hour before this interview—9:30 a.m. Thursday—the St. Louis Justice Center put out a call for service for a sudden death, and the Department of Public Safety announced that the St. Louis Police Force Investigative Unit was requested to assist the Medical Examiner.

The Force Investigative Unit, also called FIU, was formed in 2014 to investigate all instances of police shooting non-law enforcement. It’s unclear what led to this call for FIU to investigate a jail death.

Two crime lab vans were parked on the sidewalk outside the Justice Center, as at least four detectives were also investigating.

Netanya Thomas said she was just inside the Justice Center prior to the calls.

“I’m kind of shocked, because I didn’t hear anything about that, and I had just gotten released. I was in jail,” she said. “It’s just sad. I mean, there was a lady in there withdrawing, and she refused medication and medicine, and they told her that people die in here all the time, and I guess that’s why they said that.”

A spokesperson for the Department of Public Safety issued the following statement to FOX 2:

Early today after 1:00 am, at the St. Louis City Justice Center, a detainee began having a medical emergency in the Infirmary observed by fellow detainees. The detainees alerted a Correctional Officer. At approximately 1:20 am, the Correctional Officer called for medical assistance and 911 was called. Medical staff performed assessments until EMS arrived. EMS responded at approximately 1:28 am and at approximately 1:32 am, the ambulance transported the detainee to a local hospital. He was later pronounced deceased at approximately 3:35 am.

The health and safety of detainees remain the Division of Corrections’ top priority. The incident is under investigation and the Medical Examiner’s office has been contacted. Further information will be provided when available.

The St. Louis Justice Center has been the focus of many news reports lately following the Aug. 22 hostage crisis. SWAT had to rescue a guard in his 70s after he was attacked by inmates. St. Louis police are also investigating the Aug. 20 jail death of 32-year-old detainee Carlton Bernard. The Medical Examiner is awaiting blood test results, but reports an autopsy showed no signs of trauma.