Manhattan's 1,776-ft-tall One World Trade Center Officially Opens
The $3.9-billion One World Trade Center—the Western Hemisphere's tallest building, thanks to a 441-ft-tall spire—officially opened on Nov. 3, more than 13 years after the Sept. 11, 2001, terrorist attacks that destroyed the original 110-story Twin Towers. The 104-story tower—designed by architect Skidmore, Owings & Merrill, with structural engineer WSP Cantor Seinuk and mechanical engineer Jaros Baum & Bolles after an early collaboration with Studio Daniel Libeskind—has redundant and beefed-up structural and mechanical systems, and the air-supply system has biological and chemical filters. Managed by Tishman Construction Corp., construction began in 2006 (ENR 8/15/11 p. 38). The project survived controversy, a 2005 redesign for security and other delays.