Final pieces hoisted atop new World Trade Center building

The final section of the spire is raised to the top of One World Trade Center. (CNN)

The last two sections of the 408-foot spire that will sit atop One World Trade Center have been hoisted onto a temporary platform earlier this morning. The spire, essentially a giant antenna, will put the building at 1,776 feet, making it the tallest skyscraper in the nation.