Aerial Photos of 9/11 Attack

** ADDS INFORMATION REGARDING SOURCING OF IMAGE ** This photo taken Sept. 11, 2001 by the New York City Police Department and obtained by ABC News, which claims to have obtained it under the Freedom of Information Act, shows smoke billowing from the grounds of World Trade Center in New York. (AP Photo/NYPD via ABC News, Det. Greg Semendinger) MANDATORY CREDIT (AP/NYPD VIA ABC NEWS)

** ADDS INFORMATION REGARDING SOURCING OF IMAGE ** This photo taken Sept. 11, 2001 by the New York City Police Department and obtained by ABC News, which claims to have obtained it under the Freedom of Information Act, shows one of the towers of the World Trade Center in New York as it begins to crumble. (AP Photo/NYPD via ABC News, Det. Greg Semendinger) MANDATORY CREDIT (AP/NYPD VIA ABC NEWS)

** ADDS INFORMATION REGARDING SOURCING OF IMAGE ** This photo taken Sept. 11, 2001 by the New York City Police Department and obtained by ABC News, which claims to have obtained it under the Freedom of Information Act, shows one of the towers of the World Trade Center in New York as it begins to collapse. (AP Photo/NYPD via ABC News, Det. Greg Semendinger) MANDATORY CREDIT (AP/NYPD VIA ABC NEWS)

** ADDS INFORMATION REGARDING SOURCING OF IMAGE ** This photo taken Sept. 11, 2001 by the New York City Police Department and obtained by ABC News, which claims to have obtained it under the Freedom of Information Act, shows smoke and ash rising above downtown high-rise buildings and engulfing lower Manhattan in New York. (AP Photo/NYPD via ABC News, Det. Greg Semendinger) MANDATORY CREDIT (AP/NYPD VIA ABC NEWS)

This photo was taken Sept. 11, 2001 by the New York City Police Department shows smoke and ash rising in the area around the World Trade Center in New York. (AP Photo/NYPD via ABC News, Det. Greg Semendinger) (AP/NYPD VIA ABC NEWS)

This photo taken Sept. 11, 2001 by the New York City Police Department shows a World Trade Center tower burning after it was hit by a passenger jet in New York. (AP Photo/NYPD via ABC News, Det. Greg Semendinger ) MANDATORY CREDIT (AP/NYPD VIA ABC NEWS)

In this Sept. 11, 2001 photo made by the New York City Police Department and provided by ABC News Tuesday Feb. 9, 2010, smoke and ash rise as a World Trade Center tower burns at left center, after terrorists flew two airliners into the World Trade Center towers. AP Photo/NYPD, via ABC News, Det. Greg Semendinger ) MANDATORY CREDIT (AP/NYPD VIA ABC NEWS)

In this Sept. 11, 2001 photo made by the New York City Police Department a World Trade Center tower implodes in New York, after terrorists flew two airliners into the towers. (AP Photo/NYPD, via ABC News, Det. Greg Semendinger ) (AP/NYPD VIA ABC NEWS)

This photo taken Sept. 11, 2001 by the New York City Police Department and obtained by ABC News, which claims to have obtained it under the Freedom of Information Act, shows smoke and ash engulfing the area around the World Trade Center in New York. (AP Photo/NYPD via ABC News, Det. Greg Semendinger) MANDATORY CREDIT (AP/NYPD VIA ABC NEWS)

This photo taken Sept. 11, 2001 by the New York City Police Department and obtained by ABC News, which claims to have obtained it under the Freedom of Information Act, shows smoke and ash engulfing the area around the World Trade Center in New York. (AP Photo/NYPD via ABC News, Det. Greg Semendinger) MANDATORY CREDIT (AP/NYPD VIA ABC NEWS)

** ADDS INFORMATION REGARDING SOURCING OF IMAGE ** This photo taken Sept. 11, 2001 by the New York City Police Department and obtained by ABC News, which claims to have obtained them under the Freedom of Information Act, shows smoke billowing from the grounds of World Trade Center in New York. (AP Photo/NYPD via ABC News, Det. Greg Semendinger) MANDATORY CREDIT (AP/NYPD VIA ABC NEWS)