One World Trade Center in New York City officially became the tallest structure in the Western Hemisphere when its 408-foot spire was placed atop the building on Thursday.

The spire helped the landmark building reach its final and symbolic height of 1,776 feet, with 1776 being the year that the US declared its independence.

The piece was lifted slowly up the side of One World Trade Center on the morning of May 2. Initially, the spire was supposed to be installed days earlier on Monday April 29, but the weather did not permit. May 2, however, presented a warm and sunny day, the perfect conditions for the topping off of the building.

The Port Authority of New York and New Jersey said that the spire was lifted to a temporary platform atop the building and will be completely installed at a later date.

The 758 ton spire will serve as a world-class broadcast antenna, as well as a beacon warding off aircraft.  Replacing the system destroyed during the 9/11 attacks, the antenna will provide public transmission services for television and radio.

The crowning spire is a joint venture between the ADF Group Inc. engineering firm in Terrebonne, Quebec, and New York-based DCM Erectors Inc., a steel contractor, reports NBC New York.

The final section of the spire that will top off One World Trade Center is raised past iron workers to the top of the building in New York, on May 2.Reuters