Editor's note: Timberlawn has announced that it will close and stop providing psychiatric services on Feb. 16. The story below was published Jan. 18.

Timberlawn psychiatric hospital says it is voluntarily closing its doors, just a week after state officials threatened to shut down the century-old treatment center because it was too dangerous for patients.

"Our intention to close Timberlawn comes after completing a comprehensive, careful review," chief executive James Miller wrote Thursday in a letter to staff obtained by The Dallas Morning News.

He later issued a similar statement to The News, saying that the hospital's owners had decided to shutter it in December, before the state threatened to yank its license and fine it $600,000. Timberlawn is appealing those sanctions.

It’s unclear exactly when the last patient will leave Timberlawn, which was once a premier mental health facility but in recent years has had safety problems, including sexual assaults.

An employee who answered the phone Thursday said the hospital was still accepting new patients.

Miller told federal health officials that the hospital will close on Feb. 1, or as soon after that as possible, said Bob Moos, a Dallas spokesman for the Centers for Medicare and Medicaid Services.

Timberlawn is responsible for transferring patients to other hospitals, according to Carrie Williams, spokeswoman for the Texas Health and Human Services Commission.

Only 15 of the hospital's 144 beds are currently filled, she said.

Miller cited a decreased patient population as one reason for the hospital’s closure, along with the increasing availability of beds at other facilities and the cost to refurbish aging buildings on the Timberlawn campus, most of which are vacant.

He also said management is confident that Timberlawn has fixed its safety problems and now complies with federal regulations, though the results of the latest government inspection on Jan. 10 were not yet available.

As The News has detailed, children and adults trying to recover from trauma, depression or other mental conditions have gone to the hospital in East Dallas for help -- and found danger instead.

In 2014, a suicidal woman was left alone and killed herself. In 2015, a woman reported she was raped by another patient. And last fall, a 13-year-old girl who was a victim of past sexual abuse reported that a another teen patient came into her room one night and raped her.

The News does not typically name victims of sexual assault.

Inspectors found that on a night when there was just one mental health aide to watch 16 kids, the 17-year-old boy slipped into the girl's room unnoticed. The two were placed in rooms next to each other, despite the fact that a doctor had warned the boy needed to be watched for sexual aggression.

At the time, the hospital was on probation with state health officials for its previous breakdowns in care.

The company that owns Timberlawn, Universal Health Services Inc., is the largest operator of mental health facilities in the country -- and is facing a slew of government investigations, including a federal criminal fraud probe. Since 2012, the company has closed two residential treatment centers for adolescents, in Virginia and Illinois, that faced regulatory sanctions.

Last August, Massachusetts regulators closed Westwood Lodge hospital after a long series of problems involving safety and patient care.

Universal Health Services Inc., which owns Timberlawn, is facing a slew of government investigations, including a federal criminal fraud probe. (Ashley Landis / Staff Photographer)

Universal Health owns at least five other mental health hospitals in North Texas, according to its website: Hickory Trail Hospital in DeSoto, Millwood Hospital in Arlington, University Behavioral Health of Denton; Mayhill Hospital, also in Denton; and Garland Behavioral Hospital.

A 2016 data analysis by The News found that of 154 Universal Health hospitals, more than a quarter were plagued by serious safety problems.

A spokeswoman for Universal Health did not respond to multiple requests for comment Thursday.

As Timberlawn's safety problems have worsened over the last three years, its role in the Dallas-area mental health network has faded. It had been one of the few hospitals to treat large numbers of children and teenagers, but other facilities with a broader range of medical services are now taking in more of those patients, Dallas mental health experts say.

"Timberlawn represented a century-and-a-half-old model of care that we really don't need,'' said Andy Keller, chief executive officer of the Meadows Mental Health Policy Institute in Dallas.

The state oversees more than a dozen standalone psychiatric facilities in North Texas. Some general hospitals also have psychiatric units.

Colette Riel, whose sister committed suicide at Timberlawn in 2014, said she was glad that the hospital’s closure means no one else will get hurt at Timberlawn. Her sister, 37-year-old Brittney Bennetts, was known to be suicidal when staff left her alone; she hanged herself on doorknobs that the hospital knew posed a risk.

But Timberlawn’s closure is just “a drop in the bucket,” Riel said. “What about the parent company that owns all of these hospitals nationwide and their record and recklessness?”