It's a start.

A lot of people forget this (or didn't realize it in the first place), but the North and South Towers were not the only skyscrapers to collapse in New York City on September 11, 2001.

With what seems like little fanfare, 7 World Trade Center, which was the last building to collapse as a result of the 9/11 attacks, became the first to be permanently rebuilt. The new 52-story building officially opens Tuesday, local time.

The new structure boasts state-of-the-art safety features. So far, occupancy is rather low, but developers are optimistic that will change.