By BRIAN WITTE
ANNAPOLIS, Md. (AP) -- An exhaustive six-month probe found that wiring under a large Christmas tree sparked a mansion fire that spread so quickly a Maryland couple and four of their grandchildren couldn't escape, despite a functioning alarm system, a report released by federal investigators.
The Bureau of Alcohol, Tobacco, Firearms and Explosives and the Anne Arundel County Fire Department report, which concluded the fire was accidental, identified numerous hazards at the castle-like mansion near Annapolis, Maryland. The primary hazard was that although it was a residential building, it was built like a commercial building with about 16,000 square feet, not including the basement.
"Additionally, the building had been built to look like a castle so there were numerous round turrets located throughout the building," the report said. "All of these factors created potential collapse issues."
Investigators determined a 15-foot Fraser fir Christmas tree in the mansion's Great Room was capable of generating enough energy to fuel the blaze. They also found there were no timers on the Christmas lights, which had been left on for about six weeks leading up to the fire. The tree also had shown signs of moisture loss at the time of the Jan. 19 fire near Annapolis, Maryland, that killed Donald and Sandra Pyle and four of their grandchildren.
As many as 15 strands of lights were plugged into a power strip, which was plugged into a floor receptacle.
Other potential causes were identified and analyzed, but all were eventually discarded.
"Though investigators were unable to affirmatively exclude the possibility that this fire was the result of human introduction of open flame to available combustible material, there is no evidence to suggest such a thing happened," the report said, adding that "the theory of an intentional act is improbable."
According to interviews by investigators, the tree was steadily dropping needles and the branches had started drooping. Employees of the family advised that they knew that the two trees in the residence were dry, and they noted that Sandra Pyle was aware of the condition of the trees. The Pyles both wanted to keep the tree longer, because they felt like they hadn't had a chance to enjoy it, but both trees had been scheduled to be removed on Jan. 20 -- a day after the fire.
Investigators conducted controlled burns on three trees at the ATF's Fire Research Lab in Beltsville, Maryland, because there has never been any research done on a tree the size of the one in the Pyle's home catching fire. The study found burning characteristics for all three trees were dependent on their moisture content. The trees with lower moisture content ignited sooner and produced a higher peak heat-release rate, the report found. The lower moisture rate also resulted in a relatively longer burning duration, primarily due to more of the tree being consumed by the fire.
The study found it could be reasonably inferred that the amount of heat generated during the fire was "overwhelming and that it spread at an extremely rapid rate."
"These factors explain why all six occupants were unable to escape and ultimately fell victim to the fire," the report said. Donald Pyle's body was found in the collapsed debris of the great room near the spot where the 15-foot Christmas tree stood and his wife's body was found in debris from a second-floor guest bedroom near some of their grandchildren, according to the report.