By Ben Weathers
The Capital
ANNAPOLIS, Md. — Tucked behind a business park some 30 miles from where Don and Sandra Pyle’s south Annapolis mansion burned last month is the federal Bureau of Alcohol, Tobacco, Firearms and Explosives’ National Research Center.
Here, in Beltsville, federal investigators will try to re-create the blaze last month that killed the Pyles and four grandchildren.
“Fire on one hand is very simple, and then on the other hand it’s extremely complex,” said Lenwood Reeves, a certified fire investigator with the ATF.
Reeves is a liaison between about a half-dozen engineers at the lab and nearly 70 other ATF fire investigators throughout the country.
Investigators concluded last month the fire that destroyed the Pyles’ 16,000-square-foot home was caused by an electrical failure that ignited the skirt of a 2-month-old, 15-foot Fraser fir Christmas tree.
The ATF has purchased three Fraser firs, acquired from the same source as the Pyles’, and is aging them to re-create the exact conditions of the fire. Agents will ignite the trees in early April, said Special Agent David Cheplak, an ATF spokesman.
The bureau’s work on the south Annapolis blaze is no longer a criminal investigation, but Reeves declined to discuss its specifics. The bureau’s conclusions will be used for academic research, he said.
The center is essentially split into a traditional forensic science laboratory and a lab that focuses on fire investigations. Although the ATF has two other forensic science labs, in San Francisco and Atlanta, its fire research lab is the only one of its kind in the country, Reeves said.
The lab investigated 74 fires in fiscal 2013. It provides assistance to some 3,000 additional arson investigations throughout the country each year, Reeves said.
The lab conducts between 200 and 300 burns each year in two “burn rooms,” the largest of which is 16,900 square feet.
Investigators are trying to answer a series of questions, Reeve said. “How an object burned, how that fire behaved inside a particular structure, how did it ignite?”
The lab was built in the early 2000s for $180 million, said Mike Keller, its senior electrical engineer.
Most burns cost between $200 and $300, but some can cost thousands. About a decade ago the ATF spent about $40,000 re-creating a 2004 fire in a South Carolina hotel lobby, Reeves said.
To re-create a single fire, investigators conduct multiple burns to come up with a range of data. That’s why three Christmas trees were purchased for the investigation into the Annapolis blaze.
The lab uses contractors to operate complex machinery and build the structures ultimately used in burns. Many of the contractors who do the lab’s carpentry are certified firefighters who also control and extinguish the blazes, Reeves said.
Fires are ignited under large funnels called “hoods.” Inside the hoods are instruments that measure heat, chemical composition, oxygen consumption and carbon monoxide production.
“The big thing that drives our testing is how much energy is being released,” Reeves said.
The hood measures the energy produced by a fire in megawatts and kilowatts. The hood in the lab’s large burn room is 60 feet by 60 feet. The instruments inside collect data every second.
That data can then be used to create a computer model.
Inside the lab’s medium burn room on Friday was a wooden replica of a part of a building, scheduled to be burned in another ongoing investigation.
In a nearby room, engineers photographed a melted electrical appliance to figure out whether the appliance had started a fire or been destroyed by it, Keller said.
In yet another room on the forensic side of the complex are rooms where investigators sift through debris of fire and explosives to determine whether accelerants are present and, if so, what kinds.
The replica in the burn room was equipped with other instruments that will measure the velocity of gases and smoke.
Investigators typically burn smaller items like furniture in the lab’s medium burn room. They then re-create the conditions of that burn using a natural gas burner inside a larger structure.
“At the end of the day you have to put all the data together and come to a conclusion,” Reeves said.
The ATF has 67 agents trained as certified fire investigators, and another 42 considered “candidates” spread throughout the country. Candidates have to complete a two-year program in which they attend training programs and conferences throughout the country, as well as conduct their own scientific research.
The bureau’s National Response Team, which responded to the Annapolis blaze, is generally made up of about 18 to 20 people, including engineers, chemists and K-9 handlers. The team can be sent anywhere in the country in 24 hours.
In their initial response, Reeves said, agents often use software that generates 3D forensic maps of fire scenes.
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(c)2015 The Capital (Annapolis, Md.)
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