Britain's Queen Elizabeth II "died peacefully" on Thursday, Sept. 8, at Balmoral Castle, the British royal family's estate in Aberdeenshire, Scotland, according to a statement from Buckingham Palace. She was 96.
Elizabeth was Britain's longest-reigning monarch. She ascended to the throne in 1952 and, in June, celebrated her Platinum Jubilee, marking 70 years as queen.
The doors of Westminster Hall have now been opened to the public to allow people to pay their respects to the late Queen Elizabeth as she lies in state.
Lines have been forming for the last 24 hours as Londoners hope to get the chance to walk by the queen's casket.
The last member of the royal family to lie in state at Westminster Hall was Queen Elizabeth’s mother, who died in 2002.
President Joe Biden spoke Wednesday with King Charles III to offer his condolences, according to a statement from the White House.
Biden hopes "to continue a close relationship with the King," the statement said.
"The President recalled fondly the Queen’s kindness and hospitality, including when she hosted him and the First Lady at Windsor Castle last June,” the statement said. "He also conveyed the great admiration of the American people for the Queen, whose dignity and constancy deepened the enduring friendship and special relationship between the United States and the United Kingdom."
Queen Elizabeth’s four children -- King Charles, Princess Anne and Princes Andrew and Edward -- are walking directly behind the coffin during the procession.
Walking behind the queen’s children are: William, the Princes of Wales; his brother Harry, the Duke of Sussex; and the brothers’ cousin, Peter Phillips. This marked the second time since the queen’s death that Princes William and Harry were seen in public together amid reports of tension between the brothers.
Several spouses of the children and grandchildren are traveling by car: Camilla, the Queen Consort; Kate, the Princess of Wales; Meghan, the Duchess of Sussex; and Sophie, the Countess of Wessex.
Members of the queen's close personal staff are also participating in the procession.
Londoners have lined the route and were seen wiping away tears as they watched the slow and solemn procession.
Big Ben is tolling at one-minute intervals and minute guns are firing from Hyde Park.