The tenth anniversary of 9/11 (38 images)

Smoke continues to rise from the destroyed World Trade Center on September 15, 2001, in New York. September 11, 2011 marks the tenth anniversary of the terrorist attacks on the World Trade Center, Pentagon and the crash of flight 93 in Shanksville, Pennsylvania. UPI/Keith Myers/POOL

Rays of light burst off a building at One Liberty Plaza to silhouette two firefighters who are surveying Ground Zero at dawn on September 15, 2001 in New York City. September 11, 2011 marks the tenth anniversary of the terrorist attacks on the World Trade Center, Pentagon and the crash of flight 93 in Shanksville, Pennsylvania. UPI/Chris Corder

A young boy, Derek, 10 years old, sits on the corner of Christopher and Waverly street, in New York City, September 12, 2001, and draws with a stone the two World Trade Center towers being hit by planes on September 12, 2001. September 11, 2011 marks the tenth anniversary of the terrorist attacks on the World Trade Center, Pentagon and the crash of flight 93 in Shanksville, Pennsylvania. UPI/Hayden Roger Celestin

The Pentagon billows smoke after an airliner crashed into the building in a terrorist attack, causing part of the building to collapse and catch fire, September 11, 2001, in Arlington, Virginia. September 11, 2011 marks the tenth anniversary of the terrorist attacks on the World Trade Center, Pentagon and the crash of flight 93 in Shanksville, Pennsylvania. UPI/Chris Corder