A 95-year-old veteran of the Second World War who devoted many of his later years to helping refugees has died in hospital, sparking an outpouring of messages of support.
Writing on his Twitter account, Smith's son said, "At 3.39 this morning, my dad Harry Leslie Smith died. I am an orphan."
Smith was admitted to hospital on November 20 after a fall while in Ontario, Canada.
Born in 1923, Smith joined the Royal Air Force in 1944 when he was 21, and saw active service in the final year of the conflict. More recently he has achieved renown as an activist and campaigner for refugee rights.
This year he raised more than $70,000 for a book project to travel to refugee hot spots around the world and document the plight of those forced from their homes by conflict and poverty.
“Before my time dwindles down to a few precious moments, I want to travel to as many refugee hot spots as possible in Europe, North America and possibly Australia to document this preventable tragedy that may lead us to another war as gruesome as the one I helped fight against Hitler over 70 years ago,” he wrote on his crowdfunding page.
He had also spent time volunteering with refugees at the jungle camp in Calais, Northern France.
Following the trip, in a video for the UNHCR he recalled how his memories of the refugees in the Second World War drove his activism for the displaced almost 80 years later. "I can still see them. Absolutely pitiful, hungry, starving.
"When it was possible, we would stop and give them whatever excess food supplies we had on our trucks and reassure them that now they were safe.
"I think for the first time I saw a gleam of hope in their faces," he said.
His son had been updating well-wishers through his account on Twitter, which prompted an outpouring of support from figures across the world.
The 95-year-old received a message from British leader of the opposition Jeremy Corbyn who tweeted “Very sorry to hear this. Please pass on my best to Harry. We need him to get well soon as the National Health Service, and our movement, needs him”.
Smith has been a vociferous support of Mr Corbyn in recent years, even speaking at the Labour party conference in 2015 where he bought the audience to tears. "My memories stretch back almost a hundred years, and if I close my eyes, I can smell the poverty that oozes from the dusty tenement streets of my boyhood," he said.
Others tweeted using the hashtag #IstandwithHarry, a reference to his best-selling memoir Harry's Last Stand.