Updated

The Louisiana attorney general's office subpoenaed 73 employees of Memorial Hospital on Wednesday as part of its investigation of deaths at hospitals and nursing homes in the New Orleans area during and after Hurricane Katrina (search).

The subpoenas were "for all levels of personnel" and included doctors, nurses and support staff, said Kris Wartelle, a spokeswoman for Attorney General Charles Foti.

They included people who were at the hospital during the storm and its aftermath "or they knew something about it," Wartelle said.

"All we can say is that we had to issue the subpoenas to get those people to talk to us," she said.

On the Memorial campus, 34 patients died after the hospital was cut off by floodwaters, according to Tenet Healthcare Corp. (search), which owns the hospital. Tenet has said 24 of those patients were in a facility on the hospital grounds run by LifeCare Holdings Inc. (search), a separate company.

Memorial Hospital said it has not tried to keep employees from talking to investigators.

In a memo dated Oct. 14 and obtained by The Associated Press on Wednesday, Tenet's assistant general counsel, Audrey Andrews, told Memorial employees it was their decision whether to talk to investigators.

The memo advised employees to speak first to a lawyer and listed the phone number for the hospital's lawyer.

Tracie Gravolet, director of human resources at Memorial, which had 1,600 employees before the hurricane, said about a dozen had contacted her in recent weeks asking for advice on responding to investigators' calls.

Gravolet said she referred employees to Andrews' letter and did not know how many spoke to investigators. She suggested they had other, more pressing worries.

"People are concerned about their personal lives — their benefits, their 401(k) plans. They've lost their houses," she said. "The attorney general ... hasn't been the focus of my employees."

At least 140 patients at New Orleans-area hospitals and nursing homes died during the storm and its aftermath. Two owners of a nursing home in St. Bernard Parish were charged last month with 34 counts of negligent homicide for flood deaths at that facility.

Wartelle has said previously that six hospitals and 13 nursing homes in Louisiana are under investigation. Allegations include patients being abandoned, evacuated improperly or euthanized to spare them further suffering while waiting for rescuers.

Wartelle said she did not know of subpoenas issued to any other hospitals or nursing homes.