PHOTOS: 4 World Trade Center ceremony

NEW YORK, NY - JUNE 25: Construction workers Danny Conca (L) and Brian Shelly hold an American Flag attached to the last steel beam, signed by members of the crews that helped build the tower, as it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers sign the last steel beam before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers sign the last steel beam before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers Danny Conca (left) and Brian Shelly hold an American Flag attached to the last steel beam, signed by members of the crews that helped build the tower, as it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers sign the last steel beam before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction worker Travis Jensen signs the last steel beam, along with other members of the crews that helped build the tower, before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction worker John O'Shea signs the last steel beam, along with other members of the crews that helped build the tower, before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers sign the last steel beam before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: With developer Larry Silverstein (yellow tie) behind him, construction worker Frank Gasior (C) watches as the last steel beam, signed by members of the crews that helped build the tower, is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Developer Larry Silverstein (yellow tie) and Assembly Speaker Sheldon Silver (C) watch as the last steel beam, signed by members of the crews that helped build the tower, is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: With developer Larry Silverstein behind him, construction worker Frank Gasior claps as the last steel beam, signed by members of the crews that helped build the tower, is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers Danny Conca (L) and Brian Shelly hold an American Flag attached to the last steel beam, signed by members of the crews that helped build the tower, as it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction worker Ken Apple signs the last steel beam, along with other members of the crews that helped build the tower, before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers Danny Conca (L) and Brian Shelly hold an American Flag attached to the last steel beam, signed by members of the crews that helped build the tower, as it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers Danny Conca (L) and Brian Shelly hold an American Flag attached to the last steel beam, signed by members of the crews that helped build the tower, as it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers are viewed at Three World Tade Center on June 25, 2012 in New York City. A ceremony was held at Four World Trade Center as the last steel beam was hoisted 977 feet to the top of the building. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: A construction worker is viewed at Three World Tade Center on June 25, 2012 in New York City. A ceremony was held at Four World Trade Center as the last steel beam was hoisted 977 feet to the top of the building. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: A construction worker at Three World Tade Center watches as the last steel beam is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: A construction worker is viewed at Three World Tade Center on June 25, 2012 in New York City. A ceremony was held at Four World Trade Center as the last steel beam was hoisted 977 feet to the top of the building. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: One World Trade Center (left) is viewed from Three World Tade Center on June 25, 2012 in New York City. A ceremony was held at Four World Trade Center as the last steel beam was hoisted 977 feet to the top of the building. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Developer Larry Silverstein attends a ceremony before the last steel beam, signed by members of the crews that helped build the tower, is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: A construction worker is viewed at Three World Tade Center on June 25, 2012 in New York City. A ceremony was held at Four World Trade Center as the last steel beam was hoisted 977 feet to the top of the building. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Following a ceremony, the last steel beam, signed by members of the crews that helped build the tower, is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers watch as the last steel beam is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers sign the last steel beam before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Following a ceremony, the last steel beam, signed by members of the crews that helped build the tower, is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers pose with the last steel beam before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Construction workers watch as the last steel beam is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Following a ceremony, the last steel beam, signed by members of the crews that helped build the tower, is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. The trapezoidal glass and steel office building, which is designed as an architectural backdrop to the September 11 Memorial, is scheduled to open in 2013. (Photo by Spencer Platt/Getty Images)

NEW YORK, NY - JUNE 25: Developer Larry Silverstein (center) stands with Assembly Speaker Sheldon Silver (2nd L) and Congressman Jerry Nadler (R) as they sign the last steel beam, also signed by members of the crews that helped build the tower, before it is hoisted 977 feet to the top of Four World Trade Center on June 25, 2012 in New York City. (Photo by Spencer Platt/Getty Images)