3 World Trade Center, the building under construction, was hit by a part of a crane, New York City officials said on the 12th of August.
The machine struck a glass panel and broke a window at the 12th floor of the 45-storey WTC.
According to fire officials, at about 8:30 p.m., the crane lowered material to the ground and at the time, when it was bringing the cable and ball back up, wind caused the ball to hit a window.
No casualties have been reported by the police. Safety inspectors are examining the site.
As Tishman Construction spokesman John Gallagher said, the panel would be replaced.
The building, which is planned to have 80 storeys, is scheduled to be put into operation in 2018.