evidence: Joe Biden incorrectly claimed he was at Ground Zero a day after the September 11 terrorist attacks, despite his own memoir placing him in Washington DC at the time. Addressing US troops on the anniversary of the 2001 attacks, the president said he was at the site of the World Trade Center in Manhattan the day after the building’s famed Twin Towers collapsed. [...] It contradicts the account he gave of his actions after the terrorist attacks, while serving as a senator for Delaware, in his 2007 memoir, Promises to Keep.