America prepares for the 9/11 anniversary – in pictures

People at the Battery Park waterfront in lower Manhattan participate in a 'hand-in-hand 9/11' ceremony by holding hands for a moment of silence at 8.46am, the time that the north tower was hit Photograph: Chip Somodevilla/Getty Images

Andy Neale kisses his wife Yvette after a moment of silence in Battery Park, New York Photograph: Jim Young/Reuters

George W Bush and Laura Bush attend a wreath-laying ceremony at the site of the Pentagon attack, with (from left) Donald Rumsfeld, Joyce Rumsfeld, Deborah Mullen and her husband Staff Admiral Mike Mullen, and defence secretary Leon Panetta Photograph: Jonathan Ernst/Reuters

Alexis Quintanilla does some last-minute cleaning at the Pentagon memorial in Arlington, Virginia Photograph: Brendan Hoffman/Getty Images

A cyclist crosses the 14th street bridge in Washington DC Photograph: Brendan Hoffman/Getty Images

Barack and Michelle Obama walk together during a visit to Arlington national cemetery in Washington DC Photograph: Joshua Roberts/Reuters

Visitors gather at the boulder that marks the site of where Flight 93 crashed in Shanksville, Pennsylvania Photograph: Gene J. Puskar/AP

Bill Clinton wipes away a tear during an opening ceremony for the Flight 93 national memorial Photograph: Jason Cohn/Reuters

A man and woman bow their heads during the dedication ceremony for the Flight 93 national memorial Photograph: Amy Sancetta/AP

A family member of one of the victims from the Flight 93 crash walks along a section of the memorial in Shanksville Photograph: Amy Sancetta/AP

George W Bush and Joe Biden greet family members of victims of Flight 93 Photograph: Nicholas Kamm/AFP/Getty Images

Two women attend the Flight 93 memorial ceremony Photograph: Nicholas Kamm/AFP/Getty Images

Joanne Sang looks at memorial ribbons tied along the fence of St Paul's chapel in New York City Photograph: Hugh Gentry/Reuters

Workers scrub a 9/11 waterfall pool in New York Photograph: Mark Lennihan/AP

A cyclist looks up towards where the twin towers used to stand Photograph: Oded Balilty/AP

Steve Zaffarano and Andrea Vacca look for names on one of the 3000 flags set up in Manhattan's Battery Park Photograph: Chip Somodevilla/Getty Images

Mayor Michael Bloomberg prepares to march in the Labor Day parade in Manhattan Photograph: Chip Somodevilla/Getty Images

A couple view a tribute to 9/11 victims at Bryant Park in New York. The 2,753 empty chairs are in place to remember the lives lost in the World Trade Centre attack Photograph: Don Emmert/AFP/Getty Images

Visitors look out at the World Trade Centre site from a public viewing platform Photograph: Spencer Platt/Getty Images

A banner in memory of those that were killed in 2001 is displayed next to the World Trade Centre site Photograph: Spencer Platt/Getty Images

Flags are carried into St Patrick's cathedral in New York during a ceremony to honour the firemen who were killed Photograph: Seth Wenig/EPA

NYPD officers search the boot of a limousine at a checkpoint near Times Square Photograph: Justin Sullivan/Getty Images

People walk through the Empty Sky memorial at Liberty State park in Jersey City Photograph: Mel Evans/AP

Cadets place flags representing victims of 9/11 in the Field of Honour in Roswell, New Mexico Photograph: Mark Wilson/AP