12th anniversary of 9/11 (41 images)

Ruth Lamagne remembers her son, Port Authority police officer David Lamagne, at the 9/11 Memorial during ceremonies marking the 12th anniversary of the 9/11 attacks on the World Trade Center in New York. September 11, 2013. UPI/Alejandra Villa/POOL

Visitors to the Flight 93 National Memorial leave remembrances along the path leading to the "Wall of Names" on the 12th Commemoration of the terrorist attacks on the World Trade Center , The Pentagon and Flight 93 near Shanksville, Pennsylvania on September 11, 2013. UPI/Archie Carpenter

Friends and family members gather at the 9/11 Memorial during ceremonies marking the 12th anniversary of the 9/11 attacks on the World Trade Center in New York. September 11, 2013. UPI/Alejandra Villa/POOL..

Katya Busoolo pauses to remember her mom Irina Kolpakova at the 9/11 Memorial during ceremonies marking the 12th anniversary of the 9/11 attacks on the World Trade Center in New York. September 11, 2013. UPI/Alejandra Villa/POOL