March 11: This post has been updated.

Frank Minyard, the Orleans Parish coroner, has concluded that he cannot determine what caused the death of Jannie Burgess, a 79-year-old patient who perished at Memorial Medical Center after a doctor ordered that she be given multiple doses of morphine in a short period. The hospital was cut off for several days by the floodwaters of Hurricane Katrina and a number of patients were found dead with elevated levels of morphine and other drugs.

"We cannot tell what she died of except that she was extremely ill," Minyard said in a phone interview several hours before a scheduled press conference. "She had a lot of physiologic reasons to die." Minyard said his official finding was that the cause of Burgess' death was "unclassified." His ruling makes it highly unlikely that any charges will be brought in the case.

The details of Burgess' death were first disclosed in a ProPublica report published in The New York Times Magazine last August. Her medical records showed that she was repeatedly dosed with morphine after the hospital had lost power, temperatures soared, and rescue helicopters failed to arrive in sufficient numbers.

The physician who ordered the medication, Dr. Ewing Cook, said that he intentionally "hastened her demise" because Burgess, who had advanced, metastatic uterine cancer, was close to death, was being cared for by nurses whose help was needed elsewhere, and would have suffered greatly if her pain medication wore off during any attempt to evacuate her.

"Dr. Cook thinks that he knocked her off," Minyard said, "but we can't prove that. He might have, he might not have. Because it's not 100 percent proved, we have to call it unclassified." He said some of the experts he consulted pointed to the fact that Burgess' death was recorded as having occurred more than three hours after the last of the morphine injections.

Cook declined to comment for this article. Minyard said that he had not spoken with Cook during his investigation. He said that during his investigation he consulted with four pathologists who work in his office, three local experts and Dr. Michael Baden, a renowned forensic pathologist from New York.

Baden has said he has a different view of the case. In an interview several months ago, after he reviewed Burgess' records, Baden said that Burgess' death was "no question a homicide." Homicide is defined by coroners as a death caused by the action of another person. Such findings do not address the issue of intent which is critical to deciding whether a crime has been committed.

Burgess' daughter, Linette Burgess Guidi, said she had not seen the experts' determinations. She said she hoped that some sort of review board could review Cook's actions. "I understand he was under a lot of pressure," she said. "I'm not out for vengeance. I just want to know the truth, I want to know what happened." She added, "There's too many questions."

The district attorney in Orleans Parish, Leon Cannizzaro, will ultimately decide whether there will be further criminal investigation or prosecution related to Burgess' death. Minyard conducted his assessment of the Burgess case at Cannizzaro's request. In September 2009, shortly after the ProPublica report, Cannizzaro said he asked Minyard "to classify the deaths reported in" the article. Cannizzaro could not be reached immediately for comment on the coroner's decision.

In 2006, authorities arrested Dr. Anna Pou and nurses Lori Budo and Cheri Landry for alleged mercy killings at the same hospital after Katrina. A local grand jury heard evidence in the case and declined to bring charges. The nurses and Dr. Pou emphatically denied that they had murdered patients and the case prompted outrage in New Orleans where medical professionals who worked in horrific conditions after the storm were widely viewed as heroes and victims. Some close to Minyard speculated that the coroner, who recently won re-election to his 10th term, decided to postpone his determination in the case until after the election -- something Minyard denies.

Minyard, 80, said the reason he had not completed his investigation of Burgess' death before now was because his office has a great deal of work on other cases and is understaffed. "I've just got too much going," he said when contacted last December. "I just want to make sure when I do it that I have it right."

Update: Minyard's press conference has happened. For more on the conference, go to the New Orleans Times-Picayune.

The District Attorney's office has just released this statement: "Since it is the Coroner's opinion that this victim did not die as a result of being administered a lethal dose of narcotics, I cannot pursue a homicide charge at this time."