As rising floodwaters swamped New Orleans, Louisiana's chief epidemiologist enlisted state police on a mission to break into a high-security government lab and destroy any dangerous germs before they could escape or fall into the wrong hands.
Armed with bolt cutters and bleach, Dr. Raoult Ratard's team entered the state's so-called "hot lab," and killed all the living samples.
"This is what had to be done," said Ratard, who matter-of-factly put a sudden end to his lab's work on dangerous germs, which he wouldn't name.
At least Ratard's team was able to retrieve laptop computers containing vital scientific data. Many other scientists in the region weren't so fortunate, losing years of research, either through storm damage or voluntary destruction.
Not since the torrential floods from Tropical Storm Allison, which badly damaged the Texas Medical Center in 2001, has scientific research been disrupted on such a large scale. Doctors and researchers in the Crescent City became exiles overnight, indefinitely locked out of their labs and unable to see patients.
Thousands of laboratory animals - many genetically engineered with human diseases like cancer and painstakingly bred and cared for - perished along with vital tissue samples thawed in abandoned labs.
Important work on heart disease, cancer, AIDS and a host of other ailments may be lost forever to scientists at Tulane and Louisiana State universities' medical schools in New Orleans.
LSU lost all of its 8,000 lab animals, including mice, rats, dogs and monkeys. Many drowned. Others died without food and water and the rest were euthanized, said Dr. Larry Hollier, dean of the LSU Health Sciences Center School of Medicine.
About 300 federally funded projects at New Orleans colleges and universities worth more than $150 million - including 153 projects at Tulane - were affected in some way, according to an initial survey by the National Institutes of Health.
One of the biggest blows is the likely destruction of frozen urine and blood samples from thousands of patients enrolled in the Bogalusa Heart Study, the world's longest-running racial study of risk factors for heart disease.
Samples collected and frozen since 1973 thawed out when the hurricane knocked out electricity and backup generators failed at a Tulane lab in New Orleans.
"It's irreplaceable. That's decades of research," aid Dr. Paul Whelton, senior vice president for health sciences at Tulane. "It makes you want to cry."
If the blood and urine samples are damaged or contaminated, future tests can't be done using them. However, Bogalusa's chief researcher, Tulane cardiologist Dr. Gerald Berenson said he had analyzed much of the data already collected and saved it on his computer, which was not damaged.
"The Bogalusa Heart Study will go on," said Berenson who visited New Orleans, but not his lab, on Tuesday. "We'll just have to pick up the pieces from what we have."
Tulane cancer specialist Dr. Tyler Curiel was one of the few researchers who decided to ride out the hurricane in New Orleans in an effort to salvage decades worth of research.
After the storm passed, Curiel spent the first few days transferring vials from broken freezers to liquid nitrogen tanks with the help of a flashlight.
He later fled to his in-laws' house in Denver and then returned to his lab for a day, grabbing whatever he could in an effort to save blood and tissue samples from an ongoing ovarian cancer project.
But he had to leave most of his experiments behind.
"This is a dramatic blow to our research," said Curiel, who plans to temporarily relocate his lab to the University of Alabama in Birmingham. "My researchers are scattered across the country and our facilities are still contaminated."
One thin silver lining to all the lab damage: It appears that no deadly diseases were released from the area's "hot labs," where researchers routinely handle and store some of the world's most dangerous germs.
In Covington, just north of New Orleans, Tulane's high-security National Primate Research Center reported only minor damage and said none of its 5,000 research animals escaped.
Ratard, the state epidemiologist, said the lab he returned to appeared undamaged and untouched by looters. He wouldn't disclose what germs the laboratory was working on when Katrina struck.
All the labs in Katrina's path that handle bioweapons defense research involving pathogens such as anthrax reported to the Centers for Disease Control and Prevention that their security wasn't compromised, according to CDC spokesman Von Roebuck. "A few reported minor damage, but there was no issue of escape."