After burning for 56 minutes, the South Tower collapses in 10 seconds, killing approximately 600 workers and first responders in the building and surrounding area.1

2

1 “South Tower Collapses” National September 11 Memorial & Museum n.d. Web. March 17, 2011 http://timeline.national911memorial.org/#/Explore/2/Entry/537
2 “Emergency Response” 911 Digital Archive George Mason University n.d. Web. April 27, 2011 http://static.911digitalarchive.org/REPOSITORY/IMAGES/PHOTOS/2792.jpeg
Courtesy of the National 9/11 Memorial and Museum