Prince Philip
Queen Elizabeth II and Prince Philip, Duke of Edinburgh are seen during a State visit by the King and Queen of Spain, London, England, July 14, 2017. Getty Images

The Duke of Edinburgh, Prince Philip would have been left dumbstruck if he saw the news of his death published in one of the leading dailies. The Daily Telegraph published an incomplete article online Wednesday announcing Philip's death as the still-alive prince prepared for his final day of public engagements.

The story appeared on the newspaper's website and it read: "The Duke of Edinburgh, the longest-serving consort to a monarch in British history, has died at the age of XX, Buckingham Palace has announced. "Prince Philip, whom the Queen described as her ‘strength and stay’ during her record-breaking reign, passed away XXXXXXX."

The story coincided with the Duke's last public engagements before he retires Wednesday.

Read: 10 Funniest Quotes To Celebrate Prince Philip's Birthday

A note at the top of the article also read: “This file needs to be a living file – and will serve Apple News as well as be the main news story. Please stick to the format below.”

Twitter users had a field day as the Telegraph made this blunder, which is not the first in the news industry. The Sun made a similar error in May when it announced that Prince Philip would be retiring from public engagements.

While many mocked the publication for repeating the Sun's error, others tried to figure out what the Prince's reaction would be if he read the article about his death.

In what will be Philip's final engagement, he will pay tribute to those who have taken part in a 1,664 Global Challenge, which is a series of strength and endurance feats to raise funds and awareness for the Royal Marines charity. He will complete his 22,219th solo engagement since 1952, reports said.

The Duke is known for joking on several occasions about his retirement. He told celebrity cook Prue Leith at a Palace event: "I’m discovering what it’s like to be on your last legs," according to the Telegraph.

In May, when one of his well-wishers expressed sadness at the duke's decision to "stand down," Philip jokingly said: "I can't stand up much longer."

Philip has been the backbone of his wife, Queen Elizabeth II, since the time she was crowned. He has accompanied the Queen to ceremonies like the state opening of parliament, state dinners, and tours abroad.

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The British public, so used to seeing the prince accompany the Queen up the aisle to attend a church service, received a glimpse of what it might be like to see the Queen without the prince, in settings they have usually been seen together, in 2012. Prince Philip was unexpectedly hospitalized during the Queen's Diamond Jubilee celebrations, according to USA Today.

Buckingham Palace has said that despite the Duke's completion of royal duties, he might still decide to attend certain events, alongside the Queen from time to time. However, the Queen's public schedule will stay as normal; other members of the royal family will come forward in support of the monarch in her role as head of state.