In total, 2,973 people were killed in the attacks 20 years ago, excluding 19 hijackers and 26 people considered missing.
Apart from the 2,669 American deaths, 372 foreign nationals lost their lives in the 9/11 attacks—12 percent of the total—including six Polish nationals.
Five years after that traumatic experience, a survivor told Radio Poland what it was like to be at Ground Zero when hijacked planes slammed into the twin towers of the World Trade Center in New York on the bright sunny morning of September 11, 2001.
Danuta Isler talked to Leokadia Głogowska at the foot of the Brooklyn Bridge, just a few blocks away from Ground Zero.
Click on the audio player above to listen.