The death of an 89-year-old woman on the roof of UPMC Montefiore this week is prompting several investigations, and the hospital could face fines, a change in its accreditation status and a lawsuit from the woman's family.

Pittsburgh police, the state Health Department and the hospital itself will examine how Rose Lee Diggs, who suffered from dementia and heart problems, was able to wander unnoticed from her 12th-floor room on Tuesday night and go to the roof. Her body was found there by a maintenance worker on Wednesday morning. She was wearing only a hospital gown and slippers. Overnight temperatures dipped to 23 degrees.

Within 45 days, UPMC is expected to issue a report and action plan to The Joint Commission, a national organization that accredits UPMC Montefiore and more than 4,200 hospitals across the country.

Frank Raczkiewicz, director of media relations for UPMC, declined to discuss specific actions being taken by the hospital. In an e-mail message, he said, "We are reviewing our policies and procedures to prevent a similar incident and we're cooperating fully with the city of Pittsburgh police in their investigation."

The state Health Department will start its own inquiry when police and the hospital each finish their work, said Stacy Kriedeman, a department spokeswoman.

"Then we'll go in and look at what was done and what the hospital knew," she said. "If we find deficiencies, then we'll cite them."

The hospital also would be responsible for submitting a "plan of correction" and may have to pay fines to the state.

Mrs. Diggs, of Homewood, had a history of wandering, and, on at least one occasion this year, she wandered away from the Village at Pennwood nursing home in Wilkinsburg, according to neighbors.

Robert Peirce III, a lawyer for Mrs. Diggs' family, said UPMC was aware of her past, and his law firm is "in the process of getting all the paperwork together to file a lawsuit."

"The family is devastated by this," he said. "They want to get to the bottom of how this happened to their mother."

According to police, Mrs. Diggs apparently went through a fire exit about five feet from her room. The door's alarm didn't sound. She then went up two short flights of stairs, through a boiler room and onto the roof. The roof door doesn't lock.

When she was found, Mrs. Diggs had slight cuts and bruises on her forehead that suggested she had fallen.

The Allegheny County Medical Examiner's office conducted an autopsy yesterday, and the results won't be available for about eight to 12 weeks.

Police didn't release any new information.

"We're continuing our investigation," Lt. Kevin Kraus said. "We have consulted with the district attorney's office and we will continue to do so."

Mrs. Diggs' death qualifies as a "sentinel event" for The Joint Commission, which issues safety standards for patient care.

The commission is aware of the incident, said spokesman Kenneth Powers.

Under the commission's guidelines for accredited institutions, UPMC must submit a root cause analysis or face a change in its accreditation status.

About 60 to 65 percent of patients with Alzheimer's disease will wander at some point, said Lois Lutz, education and outreach coordinator for the Greater Pennsylvania Chapter of the Alzheimer's Association.

She said UPMC likely has a policy in place for dealing with such patients.

"If they do, make sure it's being practiced," she said. "Maybe even have some drills, just to make sure it's secure."

The faulty alarm on the fire door near Mrs. Diggs' room should be a main focus of the investigation, she said.

Hospitals frequently will assign a low-level staff person to monitor a patient one-on-one if they're known as a high risk to wander, said Dr. Mahmood Usman, a Torrance State Hospital psychiatrist who formerly specialized in Alzheimer's care at a private clinic in Robinson. Sometimes, such a patient will be put in a room directly across from the nurses station to be observed more closely than the rest of the patients, he noted.

"It used to be that people would be tied, and they're trying to get away from that," Dr. Usman said.

"The problem with wandering is there's no pill to treat it. A lot of other behavioral symptoms you can treat with medication," he said. "For whatever reason in this case, apparently they either didn't know she had to be closely supervised or didn't have the staff to do it ... but obviously, somebody dropped the ball."

A similar incident occurred at a nursing home in Queens, New York, in 2004, when a 79-year-old woman with Alzheimer's disease disappeared after dinner and was found on the roof. She later died from exposure to cold.

The woman, Lillie Gardner, had gone through a door that was supposed to be locked and alarmed.

"They knew she was a wanderer," said Kenneth Mollins, a lawyer who represented the Gardner family. "She walked right through that door."

Last year, the Bishop Charles Waldo MacLean Episcopal Nursing Home reached a monetary settlement with the woman's family.

The New York State Health Department issued a report that heavily criticized the nursing home's training for staff and its faulty alarm system.

The nursing home has since encouraged its staff to be more aware of patients who have a tendency to wander, said Melissa Krantz, a spokeswoman. The home has also reinforced its alarm system and the locks on stairwells.

Mr. Mollins said UPMC should face penalties for Mrs. Diggs' death.

"It's clearly a deficiency in the way they do things there," he said. "Hopefully the local authorities will cite the hospital."

In a local case that attracted widespread publicity, an elderly Crafton woman died in 2001 after she was trapped on a 40-degree night in a locked outdoor courtyard at the defunct Ronald Reagan Atrium I Nursing and Rehabilitation Center in Robinson.

Former Atrium resident Mabel Taylor, 88, was found dead on Oct. 26, 2001, after she entered the fenced courtyard through a door that was supposed to sound an alarm, then slammed shut behind her. An autopsy determined that exposure to cold triggered a fatal arrhythmia in Mrs. Taylor's diseased heart......

Investigators later learned that Atrium employees tried unsuccessfully to deceive Mrs. Taylor's family by dragging her body indoors, washing and placing her body in bed and telling her daughter that she'd died peacefully in her sleep. Court testimony also showed that Mrs. Taylor and other residents had wandered into the courtyard before, and that workers disabled alarms -- in violation of Atrium and state regulations -- to step outdoors and smoke without discovery.

An investigation of Mrs. Taylor's death later expanded to include other allegations of neglect and understaffing at Atrium. In 2005, former Atrium administrator Martha F. Bell, of West Mifflin, and the facility she operated were convicted in federal court of fraud and making false statements about health care matters. Mrs. Bell was sentenced to five years in prison and ordered to pay $50,000 in fines; the Atrium corporation was fined $490,000.

Two years later, a jury in Allegheny County Common Pleas Court found Mrs. Bell and the nursing home guilty on charges of neglect of a care-dependent person, involuntary manslaughter and reckless endangerment in the death of Mrs. Taylor. Mrs. Bell, who also was convicted of conspiring to cover up the circumstances of Mrs. Taylor's death, was sentenced to an additional 22 to 44 months in state prison.