There is no joy in Trooferville tonight: Feds: Fires took down building next to twin towers.

GAITHERSBURG, Md. (AP) - Federal investigators said Thursday they have solved a mystery of the Sept. 11, 2001 attacks: the collapse of World Trade Center building 7, a source of long-running conspiracy theories.

The 47-story trapezoid-shaped building sat north of the World Trade Center towers, across Vesey Street in lower Manhattan. On Sept. 11, it was set on fire by falling debris from the burning towers, but skeptics have long argued that fire and debris alone should not have brought down such a big steel-and-concrete structure.

Scientists with the National Institute of Standards and Technology say their three-year investigation of the collapse determined the demise of WTC 7 was actually the first time in the world a fire caused the total failure of a skyscraper. “The reason for the collapse of World Trade Center 7 is no longer a mystery,” said Dr. Shyam Sunder, the lead investigator on the NIST team.

Investigators also concluded that the collapse of the nearby towers broke the city water main, leaving the sprinkler system in the bottom half of the building without water.

This won’t stop the march toward Troof, of course, because these so-called scientists are obviously in on the plot.