Window washers at work at 1 World Trade Center

NEW YORK - Two window washers were spotted hard at work at 1 World Trade Center in Lower Manhattan on Monday morning.

The skyscraper is covered in glass windows that require frequent maintenance.

The men at work were high above the city with the Hudson River in the background as FOX 5's SkyFox helicopter was overhead about 

The building, owned by the Port Authority of New York and New Jersey, is 104 floors tall (but actually the tower only actually has 94 actual floors inside) and took about $3.9 billion to build.

It stands at a symbolic 1,776 feet tall.