On a rainy spring morning in eastern Kentucky, Greg Gorbett prepares to commit arson. His target is a tidy but cheerless one-bedroom apartment with the kind of mauve-colored carpet, couches, tables, and lamps you would find in a cheap motel. Gorbett is not the only one eager to see the place burn. A handful of other fire scientists and grad students from Eastern Kentucky University (EKU) are checking equipment in the test room as well. They have gathered at the EKU fire lab, a concrete structure in an open meadow as close to nowhere as possible, to document in exacting detail the life cycle of a blaze.
Gorbett scans the setup one last time. A foil-covered wire studded with metal probes—a thermocouple array—crosses the ceiling and hangs down the center of the space; it will measure the temperature at one-foot intervals every two seconds. A radiometer shaped like a soup can will detect changes in radiant energy. Bundles of yellow wires will carry the data to a computer-equipped truck sitting out back. There is also a man lying on the floor: James Pharr, a former fire investigator from Charlotte, North Carolina, wearing a fire-resistant suit and oxygen mask, who will record the event with a thermal- imaging camera.
Gorbett lights a pan of flammable heptane under an end table and then quickly exits the room. The fire begins as a glowing ball and then reaches up and curls around the tabletop like a claw. Quickly it moves to the adjacent couch, which bursts into flames. Modern cushions are made of polyurethane foam, and despite their fire resistant–covering (introduced in the 1970s to protect against smoldering cigarettes), they are basically solidified petroleum. A modern couch can release the heat equivalent of a 3 million watt lightbulb.
The fire doesn’t burn the couch so much as melt it, like a marshmallow over a campfire. Flaming liquid drips onto the floor, forming fiery puddles, some of which burn through the carpet. Pharr squiggles out of the room, dragging his camera. Curtains drop burning fragments that in turn start their own flames. The couch across the room catches fire, although no other source of fire has touched it. “Radiant heat,” Gorbett explains.
Bill Hicks, monitoring the fire on his computer in the truck, is calling out temperatures over the walkie-talkie. “Five ninety,” he says, reading the measurement at the ceiling in degrees Celsius. That translates to almost 1100 degrees Fahrenheit. The room is obscured by a layer of roiling black smoke. A lightbulb pops. The carpet catches fire. The window cracks. “Better get back,” Gorbett says, and we retreat from the window. The smoke layer descends like a curtain almost to the floor. “Seven sixty at the ceiling,” calls Hicks. Fourteen hundred Fahrenheit. The radiometer spikes.
