September 6: The World Trade Center Transportation Hub began construction on this date in 2005

On September 6, 2005, construction began on the World Trade Center Transportation Hub. Designed by Spanish architect, artist, and sculptor Santiago Calatrava, the 800,000 square foot edifice features soaring spires meant to evoke the "gesture of a child releasing a dove into the air." The $3 billion project, which is scheduled for completion by 2015, will house the PATH and connect 13 subway lines with the World Financial Center. Its open atrium will allow light to filter to rail platforms 60 feet below ground, lighting pedestrian walkways as illustrated by the video below.