The Statue of Liberty, seen from a vantage point in Jersey City, New Jersey, as the lower Manhattan skyline is shrouded in smoke following the Sept. 11 terrorist attacks on the World Trade Center in New York. Photo taken on September 15, 2001. #

Smoke pours from a gaping hole and the upper floors of the World Trade Center's North Tower, shortly after hijackers crashed American Airlines Flight 11 into the building on September 11, 2001 in New York City. #

United Airlines Flight 175 flies low toward the South Tower of the World Trade Center, shortly before slamming into the structure. The north tower burns after an earlier attack by a hijacked airliner in New York City, on September 11, 2001. #

Flames erupt from the South Tower of the World Trade Center, after it was struck by hijacked United Airlines Flight 175, in New York City, on September 11, 2001. The aircraft crashed into the tower traveling at a speed of approximately 586 miles per hour. #

Moments after United Airlines Flight 175, with 56 passengers (including the 5 hijackers) and 9 crew members, struck the South Tower of the World Trade Center between floors 77 and 85 on September 11, 2001, in New York City. #

Some of the estimated 10,000 gallons of jet fuel aboard United Airlines Flight 175 erupts in a fiery blast from the side of the South Tower of the World Trade Center after the plane crashed into it on September 11, 2001, in New York City. #

Smoke billows from the World Trade Center in lower Manhattan in this image taken by a U.S. Geological Survey satellite that flew over the region at about 9:30 a.m. on Tuesday, September 11, 2001. #

A man leaps to his death from a fire and smoke filled North Tower of the World Trade Center, on September 11, 2001 in New York City after terrorists crashed two hijacked passenger planes into the twin towers. #

This photo from a Pentagon surveillance camera shows the fireball that resulted when the hijacked American Airlines Flight 77, with 58 passengers and 6 crew members aboard, slammed into the Pentagon on September 11, 2001. #

Medical personnel and volunteers help injured people outside the Pentagon after a hijacked commercial airliner crashed into the southwest corner of the building, on September 11, 2001. #

Debris rains down on the street as the South Tower of the World Trade Center collapses after hijacked planes crashed into the towers on September 11, 2001 in New York City. #

Mark Stahl of Somerset, Pennsylvania displays a photo he took early on September 11, 2001 after United Airlines Flight 93 crashed just outside of Shanskville. Stahl heard the crash and wandered up to the site where he took the photo before the area was cordoned off by rescue workers. The plane crashed shortly after two hijacked commercial planes slammed into the twin towers of the New York's World Trade Center, causing both 110-story landmarks to collapse. #

An FBI aerial photograph shows the crash site of hijacked United Airlines Flight 93 in Shanksville, Pennsylvania, on September 12, 2001. The Boeing 757 was headed from Newark, New Jersey, to San Francisco when it made an abrupt turn near Cleveland and veered back east across Pennsylvania before crashing in Shanksville, killing all 44 aboard. Flight 93 was the fourth plane to crash in a coordinated terrorist attack that included New York's World Trade Center and the Pentagon, and the only one that didn't take lives on the ground. #

Firefighters and emergency personnel investigate the scene of the fatal crash of United Airlines Flight 93, on Tuesday morning, September 11, 2001 near Shanksville, Pennsylvania. #

This photo taken September 11, 2001 by the New York City Police Department shows smoke and ash engulfing the area around the World Trade Center as the North Tower collapses in New York. #

Dust, smoke and ash engulf buildings around the World Trade Center in New York City, after the collapse of both towers on September 11, 2001. Photo taken by the New York City Police Department. #

People run from the collapse of World Trade Center towers in New York, on September 11, 2001, after terrorists crashed two hijacked airliners into the World Trade Center and brought down the twin 110-story towers. #

The North Tower of the World Trade Center dissolves in a cloud of dust and debris about a half hour after the first twin tower collapsed, on September 11, 2001. The photo was taken from across the Hudson River in Jersey City, New Jersey. #

Rubble and ash fill lower Manhattan streets in an apocalyptic scene after two hijacked airliners were crashed into the towers of the World Trade Center in New York, collapsing them and killing thousands. #

New York City firefighters pour water on the wreckage of 7 World Trade Center in New York City early on September 12, 2001. 7 World Trade Center was destroyed along with both the landmark World Trade Center towers after being struck by planes in a terrorist attack on September 11. #

Rubble covers the tracks of the New York City Subway #1 and #9 lines in the Cortland Street station under the World Trade Center, in this photo taken shortly after the attacks of September 11, 2001. According to the New York Times, New York City Transit officials determined that the damage was so extensive, that more than one mile of the line would have to be rebuilt. #

A man stands in the rubble of the World Trade Center in New York City, calling out, asking if anyone needs help, after the collapse of the World Trade Center Towers on September 11, 2001. #