The owners of a nursing home where 35 patients died in the aftermath of Hurricane Katrina were indicted Wednesday on charges of negligent homicide and cruelty to the infirm.

Salvador and Mabel Mangano were initially arrested about two weeks after the Aug. 29, 2005, storm. The Louisiana attorney general booked them on negligent homicide charges, but a grand jury was unable to convene for months because the court system was hobbled by damage to government buildings and the displacement of residents.

The couple remained free on bond Wednesday. They owned St. Rita's nursing home in St. Bernard Parish, a coastal suburb of New Orleans badly flooded by Katrina.

Attorneys in the case were prevented from commenting by a gag order.

The Manganos were originally arrested on 34 counts of negligent homicide, but the grand jury added a 35th count in its indictment, representing a body that was found later. The grand jury also added the cruelty charges.

The indictment for cruelty alleges the couple "intentionally or through criminal negligence" mistreated or neglected 64 patients. It is believed to cover both patients who died and those who survived.

The Manganos were to be formally booked on the cruelty charges at an Oct. 4 hearing.

More than 30 lawsuits have been filed against the couple by patients injured at the nursing home and the families of people who died there.

In a lawsuit filed last month, the couple sued the government, saying federal, state and local officials failed to keep residents safe and evacuate vulnerable citizens as the storm approached.

The Manganos have argued that their hurricane plan — to keep frail residents in place with food, water and generators rather than risk moving them — was a responsible course of action, and if the levees had held, the tragedy would have been avoided.

The Manganos' attorney, James Cobb, has stressed that the nursing home never flooded before Katrina and the Manganos worried that an evacuation would kill some of their elderly patients.

In another high-profile case, authorities are evaluating evidence to present to a grand jury about a doctor and two nurses accused of killing patients with painkillers in the chaotic days after the hurricane.

Dr. Anna Pou and nurses Cheri Landry and Lori Budo were arrested July 17 and released without bond. They were booked on suspicion of second-degree murder involving four trapped and desperately ill patients ranging in age from 62 to 90.

Attorneys for the three say they are innocent.

Katrina flooded 80 percent of New Orleans and virtually wiped out neighboring St. Bernard and Plaquemines parishes. The Louisiana death toll was nearly 1,600.