The White House said the anthrax death of a New York hospital worker today is cause for concern and that preliminary tests of her home and workplace showed no indication of the anthrax bacteria.
"This is an event of concern and the president is discussing with his team", White House spokesman Mr Ari Fleischer told reporters.
"The president expresses his condolences and sympathy to the families of the woman who died", he said.
The death was the first of four anthrax fatalities in the last month that had no immediately evident link to news media or the postal service.
The FBI was intensively investigating the case. It was trying to trace any travels and contacts the woman, identified as Ms Kathy Nguyen of the Bronx, may have had, Mr Fleischer said.
Authorities were also conducting an autopsy to learn whether the bacteria that infected the woman was related to that involved in other recent anthrax deaths, he said.
The woman's home and office have been tested for anthrax, he said.
"All the results of both her home and her office are preliminary negative", Fleischer said.