The upper floors of the World Trade Center tower burns after terrorists flew an airliner into it.
AP Photo/NYPD/Det. Greg Semendinger
Smoke billows from a World Trade Center tower in New York, after terrorists flew two airliners into the towers.
AP Photo/NYPD/Det. Greg Semendinger
The first World Trade Center tower begins to implode.
AP Photo/NYPD/Det. Greg Semendinger
The World Trade Center tower implodes.
AP Photo/NYPD/Det. Greg Semendinger
Smoke and ash engulf lower Manhattan after the tower collapse.
AP Photo/NYPD/Det. Greg Semendinger
Smoke and ash engulf the general area of the World Trade Center.
AP Photo/NYPD/Det. Greg Semendinger
Ash engulfs lower Manhattan.
AP Photo/NYPD/Det. Greg Semendinger
Smoke and ash rise as a World Trade Center tower collpsed and burns .
AP Photo/NYPD/Det. Greg Semendinger
Smoke rises as ash consumes lower Manhattan.
AP Photo/NYPD/Det. Greg Semendinger
Ash covers the buildings near the World Trade Center after the collpase.
AP Photo/NYPD/Det. Greg Semendinger
The entire lower Manhattan is covered in ash and smoke.
AP Photo/NYPD/Det. Greg Semendinger