We all took them for granted as a permanent part of the Manhattan skyline. Now the Twin Towers are gone.
It's still hard to accept, especially for those of us who worked in the World Trade Center or have happy memories of visiting for a meal at Windows on the World, a view from the World Trade Center Observatory, or even a mundane errand in one of the shops in the World Trade Center Concourse.
These photos are for everyone who likes to remember the glory days of the World Trade Center -- a landmark that some called ugly, but that was nonetheless a huge part of daily life in Manhattan for more than 30 years.
Find events to mark the 10th anniversary of 9/11 in New York City.
Visit the September 11th Memorial in Lower Manhattan.