Federal authorities looking for the source of the anthrax that killed four persons have focused on possible acquaintances of a 61-year-old Vietnamese woman who died from exposure to the bacteria with no obvious explanation of how she came in contact with it.
Law-enforcement authorities said the FBI-led investigation has targeted for questioning current and former friends, co-workers, neighbors, family members, an ex-husband who disappeared several years ago, a former boyfriend and others who might have known Kathy T. Nguyen, who was buried on Monday.
Investigators have traced her route to and from work, including the No. 6 train she took daily, interviewed business owners where she was known to shop and questioned those who might have information on what has turned out to be a very private life.
Agents interviewed those who turned out to view her body at a Bronx funeral home and many of those who attended her funeral.
Mrs. Nguyen, a stockroom clerk at the Manhattan Eye, Ear and Throat Hospital who lived alone, died of inhalation anthrax three days after checking herself into a hospital. Investigators and federal health officials found no anthrax in her third-floor apartment, on her clothes, in her mail, her car or in her basement work area at the Eye, Ear and Throat Hospital, where she had been employed for 10 years.
She had no known contact with any of the anthrax-laced letters that have killed three others or caused lesser skin infections in 13 others.
“There is an explanation for this death, which so far has eluded investigators,” said one federal official familiar with the ongoing probe. “But they are determined to find out what happened to this woman, to locate the source of the anthrax that led to her death.”
No one claimed her body following the funeral service at St. John Chrysostom Roman Catholic Church in the South Bronx neighborhood in which she lived. Her death has officially been ruled a homicide.
Investigators are trying to determine with whom Mrs. Nguyen may have come in contact on purpose or in passing in the weeks after the September 11 attacks on the World Trade Center and the Pentagon and in the days before Oct. 25, when she checked into the hospital. The discovery of that information, authorities said, could lead to those responsible for the anthrax letters.
“It’s certainly possible she was exposed in a chance encounter, one that proved fatal,” said another official close to the probe.
Authorities said a number of Mrs. Nguyen’s neighbors have been interviewed by investigators about her habits, family, friends and acquaintances, although little information was obtained.
They said the woman, who left Vietnam after the fall of Saigon in 1975, rarely spoke about a former husband who left several years ago for Germany after they were divorced or about a son she had who died years ago in an automobile accident.
They also said Mrs. Nguyen, who owned a bar in Saigon and later worked at the U.S. Embassy, had a boyfriend, but he had not been around for several years and she had not dated since then. A cousin from Seattle visited several years ago, they said, but has not been seen since. The cousin did not attend the funeral, and investigators believe she has no other relatives living in the United States.
The inquiries are part of what the FBI’s Joint Terrorism Task Force, which is investigating the death, hopes to be a biographical portrait of the woman, which could help investigators learn how and where she became infected. The portrait has, so far, outlined a life that consisted mainly of trips by Mrs. Nguyen to work, church, a market and a laundry, authorities said.
Two postal workers at the Brentwood Road Mail and Processing Facility in Northeast Washington died from inhalation anthrax, as well as a 61-year-old photo editor at American Media Inc. in Florida. They either handled or received mail containing what authorities said was a potent, finely milled strain of the bacteria.
Six others have developed cases of inhaled anthrax, but are said to be recovering.