Hundreds of airline crash experts, engineers and forensic scientists have converged on Texas and Louisiana to help retrieve pieces of the space shuttle Columbia.
In Texas, about 300 people from 30 government agencies were collecting thousands of pieces of debris – some as small as a pebble and others as big as a car.
The bits will be taken to Barksdale air base in Louisiana, where engineers will sift through them in search of clues to what caused the shuttle to break apart over Texas on Saturday morning, just minutes before landing.
The experts will try to reconstruct what is left of Columbia, and establish a sequence of how each part peeled off during its high speed re-entry into the atmosphere.
The salvage operation alone is a formidable task, covering an area that stretches from the rolling hills of East Texas to a suburb of New Orleans, where authorities found what could be insulation from Columbia.
Louisiana state police confirmed more than a dozen chunks of debris in eight different parishes.
However, the search for wreckage has focused on Texas, where Governor Rick Perry said 33 counties – from north of Dallas all the way to the Gulf Coast - had reported finding debris.
The heart of the operation is in the pine woods of East Texas, a region known for its thick forests of pines and oaks, expansive farm land and cow pastures.
The area is home to four national forests, covering almost 700,000 acres, and two reservoirs that together span about 300,000 acres.
While the region is a sanctuary for hunters, boaters and anglers, its challenging terrain makes the job facing the Columbia recovery teams that much more difficult.
“This is forest – dense forest,” said James Kroll, director of the Emergency Geospacial Mapping Centre at Stephen F Austin State University in Nacogdoches.
“There is no way to describe how many pieces there are and how spread over the landscape they are.
“Ten years from now, folks are going to be walking around the woods and finding stuff.”
In Nacogdoches County alone, authorities have logged more than 1,200 confirmed debris sites. State troopers and local authorities are manning 130 spots, alongside two-lane highways, restaurants and ranches, to ensure curious scavengers do not make off with any evidence.
Though local officials had too few bodies to protect every piece discovered, they said Nasa had provided a list of priorities: anything that could contain data or resembles computer circuitry, or potentially radioactive materials.
Kroll has 10 technicians fanned out across the county using GPS handsets to log the precise location of wreckage for a debris map that could aid recovery teams.
Among the items discovered so far: a car-size chunk that splashed into Toledo Bend Reservoir on the Texas-Louisiana state line, a seven-or-eight-foot door-like fragment, what resembles part of a windscreen and a six-foot long object authorities suspect could be part of the landing gear.
In San Augustine, just east of Nacogdoches, Larry Epps placed a 55 gallon barrel to protect a piece of metal that landed in his hay meadow.
“If it hit me, my wife would have been a widow,” he said of the hollow grey object that looked like a tyre.
He later found what appeared to be a circuit board about 100 yards away from his front yard and a half dozen two-by-two-inch metal pieces in his meadow.
Marc Masferrer, editor of a local newspaper, said a landowner led him to what appeared to be a seat from the shuttle in a pasture 20 miles west of Nacogdoches.
There have been more grim discoveries – human remains, including a leg, torso, thigh bone and skull. Nasa confirmed the remains of some of the seven Columbia astronauts had been recovered.
Through thick woods that are home to wild hogs and bobcats, 75 volunteers and police officers carried out their hunt near Hemphill on the Louisiana line.
About 40ft into the forest, a searcher shouted, “Hold!” when he spotted a chunk of metal dangling from a branch. A volunteer marked it with a red flag.