The Freedom Tower

Builders of the Freedom Tower poured a bad batch of concrete into the foundation of the skyscraper replacing the World Trade Center, according to press reports, and the Associated Press says contractors have spent the last few weeks removing it after tests showed it wasn’t strong enough, officials said.

“About 50 cubic yards of concrete was jackhammered away from the core foundation of the 1,776-foot tower under construction at ground zero,” the AP says. “More than 22,000 cubic yards of concrete have been poured so far, and no other batches have failed strength tests, said Steve Coleman, spokesman for the building’s owner, the Port Authority of New York and New Jersey.”

The tower, the symbolic replacement to the twin towers destroyed on Sept. 11, is being built with concrete stronger than any other building in New York City.

The foundation should be able to withstand 14,000 pounds per square inch, about three times the strength of concrete in an average home and over five times the strength in a sidewalk. A tower rebuilt north of ground zero two years ago, 7 World Trade Center, was built with concrete at a strength of 12,000 pounds per square inch, officials said.