In 1943, 18-year-old Bill Caldwell wrote a postcard to his uncle Fred in Liverpool describing his first week in England's Royal Navy during World War II.
"Post [this] early in the day," he told the Royal Mail, according to the BBC.
The postcard was finally delivered to Caldwell's family home 77 years later. Both Caldwell and his uncle have died, but a distant relative, Jack Elomaa, lives at the address and alerted Caldwell's six children to the postcard's arrival.
"It was the most surreal thing on a Friday night to suddenly read a postcard that Dad had written 77 years ago when he was training to be a sailor in the Navy," Caldwell's daughter, Joanna Creamer, told the BBC.
In the letter, Caldwell expressed his excitement about the Navy, which he had wanted to join since he was 15.
"Well I am in blue at last. I did not think it would be like this - you don't get much time for yourself, do you?" Caldwell wrote.
The note continues: "But I like it alright. I will write a letter to you all when I get half a chance so will you hold on a bit? I have 19 weeks here yet. "Give my love to everyone."
During his service, Caldwell was deployed on a minesweeping mission ahead of the war's historic D-Day operation, according to The Daily Mail. The invasion of Normandy on June 6, 1944 has been described as the most critical moment in America's efforts to help liberate Western Europe from the Axis powers during World War II.
Caldwell also visited Japan after the nuclear bombings of Hiroshima and Nagasaki to help transport prisoners of war, according to The Daily Mail. He rose to the rank of Able Seaman and was awarded four medals for his service.
Caldwell left the Navy in 1946 and found work as a plumber before moving to Somerset in southwest England with his family in 1964, The Daily Mail reported. His children are spread out throughout the country, living in Surrey, Norfolk, Somerset and Bristol.
"It's a crazy story and it's hard to believe," Caldwell's daughter, Elizabeth, told The Daily Mail. "To get this little message from my dad felt like a really special thing for us all."
In a statement to the BBC, a Royal Mail spokesperson said the postcard was "likely … put back into the postal system by someone recently, rather than being lost or stuck somewhere in the network."
The surprise comes at the same time Caldwell's family is preparing for the anniversary of the death of his granddaughter Fiona "Fi" Braidwood, who died 2016 in a car crash at 17 years old, The Daily Mail reported.
Her mom, Vicki Caldwell, set up a charity in her honor called FEES Fund, which helps children and young adults pay for education and extracurricular activities.
Reflecting on the letter and anniversary, Elizabeth said, "It's been a very emotional and special time for us and has brought lots of things up."