Now leasing: the site of not one but two terrorist attacks. Rent prices for One World Trade Center are being slashed nearly 10 percent with six months left before the tower is set to open its doors. The 1,776-foot building is only 55 percent leased, according to the owners. "When we started in 2011, everybody expected the economy to take off, and obviously that hasn't happened," says owner Douglas Durst, who bought the tower from the Port Authority of New York. The formerly named "Freedom Tower" raked up an estimated $3.9 billion in construction costs.