Masri, who on Thursday will receive the Knight International Journalism Award in Washington, worked to bring the pain, suffering and destruction wrought on Syria's Aleppo to the world's attention, first with a camera phone and later working for AFP.
Anti-government protests broke out in Syria in 2011, and the government's brutal response sparked a civil war that wracked swathes of the country and took almost everything from Masri but his life.
"During these years, I lost many friends, I lost many relatives," said Masri, a soft-spoken 26-year-old with a short black beard.
"I pretty much lost everything," he said. "My future, my family, everything."
Asked why he remained as long as he did, he responded: "I love Aleppo."
He said he likened himself to a fish that, when taken out of water, would die.
Masri left his home city in December 2016 after a harrowing final few days of shelling, sniper fire and the destruction of a treasured camera.
He now lives in Paris, but working as a journalist in the French capital would not compare with the story he had been covering.
- Detained and wounded -
"I want to be on the ground again," Masri said of reporting on conflict.
"I feel that I'm useful in those areas," he said. "I want to shed light on the truth."
Before the war, Masri liked photography but had little experience with it, using an old camera to take photos of the occasional event such as a birthday or graduation.
He first used a phone to take images of the conflict and posted them to social media. He later bought a camera, and started working for AFP in 2013.
"There were no foreign journalists, there were no photographers, there was nothing," he said of what motivated him to start documenting the conflict.
Foreign reporters later arrived in droves, but the threat of kidnappings and other dangers subsequently kept them away again.
Masri, however, stayed on.
Much of his work focused on the devastation inflicted by the war: the shattered buildings, cratered streets, the wounded and the dead.
But he also covered -- and survived -- other impacts of the conflict, including severe shortages of food and fuel.
Masri was detained twice: for a month by Assad's forces, and for half a year by the Islamic State jihadist group.
And he was twice wounded in a way he described as serious: one time in his leg and another in his hand.
The former was worse, as it kept him from walking for four months, but the latter also posed problems for his work.
"Of course, it's very hard," he said of using a camera one-handed. "You can't control the camera, adjust the focus."