HUDSON, N.H. (AP) – The state is investigating how an 89-year-old resident of Fairview Nursing Home died of hypothermia last week.

Investigators with the state Department of Health and Human Services are reviewing the nursing home’s security procedures, which failed to prevent Harriet Low from wandering into the facility’s courtyard at night.

“We’ll investigate whether or not the facility had done what it needed to do,” said Brook Dupee, chief of the department’s Bureau of Licensing and Certification.

The investigation is expected to be complete within 10 days.

Employees at the nursing home found Low lying unconscious in the courtyard around 4:45 a.m. Friday. The temperature outside had dipped below freezing overnight.

Brian Courville, the facility’s administrator, said the home’s staff checks on residents at least every two hours and had last seen Low in her bed around 3 a.m.

“They did their rounds,” he said. “All the security systems and locking doors worked. I don’t fault the system here.”

Courville said two doors lead to the courtyard and are locked by magnets that are released by pressing a button. He said Low often went into the courtyard with her family.

Courville also said Friday’s late-night visit to the courtyard was not Low’s first. He said the nursing home still is conducting its own investigation of the incident.

“We don’t want to lock it down like a prison,” Courville said. “We want them to have access to the outside.”