Advances in forensic science since the Sept. 11, 2001, terror attacks may help Canadian authorities identify the remains of dozens of people killed in what may be the country’s worst rail accident in more than 100 years.
Even tiny shards of bone may be helpful to scientists, said Mark Desire, assistant director of the DNA World Trade Center Identification Project in New York, which is still working to identify thousands of skeletal fragments. His agency tests each piece multiple times and is devising new methods to access DNA in the cells so it can return the remains to the families.
About 50 people are missing or were confirmed dead after a Montreal, Maine & Atlantic Railway Ltd. train carrying 72 carloads of crude oil barreled Saturday into Lac-Megantic, about 250 kilometers (155 miles) east of Montreal. The crash at about 1 a.m. incinerated 30 buildings in town, including the Musi-Café bar where the police say many patrons probably died.
“Fire, chemicals and even water destroy DNA,” Desire said in a telephone interview. “For the thousands of remains that yielded no DNA profile, the techniques of the day weren’t good enough, so we’ve developed new techniques. With today’s technology, if even small bits of bone survive, they may be able to generate a DNA profile. You never know until you try.”
What used to be the heart of the small lakeside town now looks like a post-apocalyptic wasteland. Buildings close to the blast were decimated, while those further from the tracks have some walls standing. Firefighters are still working to control hot spots burning in the wreckage. None of the 20 bodies discovered thus far were identifiable.
“We are confident that we are going to be able to get DNA from the bodies that we recovered on the site,” said Genevieve Guilbault, a spokeswoman for the Quebec coroner’s office, in a telephone interview. “We are actually expecting to get some identifications in the next few days.”
DNA tests and dental records will be needed to identify the victims because of the fire’s intensity, she said. Compiling an accurate record of the missing is a critical step, since trying to match relatives with a long and inconsistent list increases the chance of false associations, said Bruce Budowle, director of the institute of applied genetics at the University of North Texas Health Science Center in Fort Worth.
There have been improvements in every step of the process in the dozen years since terrorists hijacked and crashed four commercial airlines at three sites, damaging the Pentagon and leveling the World Trade Center in 2001, forensic experts said.
There is better extraction of DNA from the remains, greater sensitivity for detecting even small amounts of genetic material and improved databases to manage and track the information, said Howard Baum, director of the office of forensic science in New Jersey and former deputy director of the forensic biology laboratory in New York City’s medical examiner’s office.
Extracting DNA from bone is one of the most difficult ways to get genetic material, according to Desire. The method, once done by hand, is now performed using a machine that uses vibration to pulverize the bone sample into the finest powder possible. Liquid nitrogen, detergents and decalcifying agents are added to help gain access to the cells and the DNA inside.
“The more cells you break open, the more DNA you have to work with,” he said. “You may have a large sample, but the DNA may be all but destroyed. Here in New York, we are generating DNA from very small bits of burned bone.”
The Quebec coroner’s office is focusing on DNA as it works to locate, catalog and compare the remains. The agency asked families to bring in razors, toothbrushes and hairbrushes so it can gather samples. Genetic samples from close relatives may be needed to hone in on victims whose personal belongings may have been burned by the fire, hampering a direct genetic comparison.
“The more challenging the sample, the more degraded, the less likely you’ll get markers you can use for identification,” said Budowle, the former top scientist at U.S. Federal Bureau of Investigation who helped build the agency’s DNA laboratory. “The technology over the years has improved quite substantially to extract DNA, improve the quality and repair of the DNA and identify other genetic markers.”
Scientists can now take damaged DNA, enhance small portions that are still useful, and amplify those over the damaged parts, Budowle said. Even if you improve the sample, it can still be very dirty, contaminated with chemicals from the environment or a fire, he said. There are now techniques that resist the contaminants and allow technicians to extract DNA, he said.
Collecting the samples is the first hurdle, said Howard Cash, president of Gene Code Forensics, an Ann Arbor, Michigan-based bioinformatics company that specializes in DNA analysis. His company devised the Mass Fatality Information System used to identify 2,749 people who were killed in the Twin Towers on Sept. 11, 2001. New York’s recovery efforts yielded 20,000 pieces of remains, which were compared to thousands more reference samples from family members in a kinship analysis.
“After getting whatever DNA profile they can from the remains, the next step is an information management problem,” Cash said in a telephone interview. “The system can work with very complicated family trees. The software has been developed to do sophisticated analysis and determine the amount of confidence you can have in the accuracy of the information.”
Accuracy is critical, and it takes time, the experts said.
“I know everyone is grieving, and the sooner you identify everyone the sooner they get closure,” Baum said. “But you have to do this right. If you rush to do it, that’s when mistakes can happen. It’s better to do it a little slowly. The consequences of doing it wrong are tremendous.”
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