What Happens Now the Queen Has Died? Operation London Bridge Explained

With the death of Queen Elizabeth II at the age of 96, a watertight plan that has long been put into place for when the monarch passes away has been implemented — Operation London Bridge.

"When the queen dies, the House of Windsor and the Palace will go into super overdrive," said William Booth, London bureau chief for The Washington Post, in a video shared by the news outlet on Thursday.

The day that the queen passes away will be known as D-Day, on which her private secretary will call the prime minister to announce: "London Bridge is down."

This news will then be shared with the governments where the queen is also head of state. Those nations include Canada, Australia, New Zealand, Belize, and the Caribbean islands of Jamaica, St. Lucia, St. Vincent and the Grenadines, Grenada, the Bahamas, and Antigua and Barbuda.

Once those governments have been informed, the news will be shared with the dozens of other countries that make up the Commonwealth.

A news flash will then be sent to the U.K. Press Association and major media outlets across the globe.

Meanwhile, a rarely used alarm for national emergencies will be activated at the BBC, where all of the news anchors will be required to wear black, and the usually red BBC logo will be switched to black.

Also dressed in black, a staffer at Buckingham Palace will post a sign outside London's Buckingham Palace announcing the queen's death in a message that will be shown in identical form on the royal family's website.

All of the flags will be lowered to half-staff and bells will toll across the city.

With the queen's eldest son, Prince Charles, unofficially becoming the head of state, he will be required to make his first speech as monarch on the evening of her passing.

These plans will apply should the queen die in London. Should she pass away outside of the English capital, the flags will be raised again at 11 a.m. the day after her death and Charles will officially become king.

As part of his first duties as king, Charles will travel to Scotland, Northern Ireland, and Wales to attend services honoring his mother.

Back in London, Westminster Hall will be closed for cleaning and funeral preparations.

Four days after the queen's death, there will be a procession from Buckingham Palace to Westminster Hall, where she will lie in state for four days ahead of her funeral.

After dignitaries have visited the queen, members of the public will be permitted access to pay their respects, with hundreds of thousands of people anticipated.

The funeral will take place on the ninth day, when bells covered in leather pads will ring in muffled tones. The coffin will then be transported to Westminster Abbey, where the funeral will take place from 11 a.m.

With a total of 2,000 mourners expected at the service, members of the public will be able to watch the service in its entirety on TV, though the faces of the royal family will be shown during prayer.

Following the service, the queen will be transported to Windsor Castle, where she will be laid to rest alongside her late husband Prince Philip, and her father, King George VI.

"It'll just be a phenomenal 10 days of pomp and circumstance," Booth told The Washington Post. "They designed it that way, and that is the genius of this House of Windsor and this monarchy, that they know how to put on a good show."

Shortly after the announcement concerning the queen's health, the BBC suspended usual programming until 6 p.m. U.K. time and members of the royal family began making their way to Balmoral Castle, where Elizabeth has been spending her summer holiday.

Prince William's children had their first full day at their new school near Windsor Castle but will have returned home to find their father has already traveled to Scotland.

Prince Harry and Meghan Markle were due to attend the WellChild Awards in London on Thursday, but their spokesperson confirmed they planned to travel to Balmoral, too.