In the spring of 1965, within weeks of 3,500 American Marines arriving in Vietnam, a 39-year-old Briton named Larry Burrows began work on a feature for LIFE magazine, chronicling the day-to-day experience of U.S. troops on the ground – and in the air – in the midst of the rapidly widening war. The photographs in this gallery focus on a calamitous March 31, 1965, helicopter mission; Burrows’ “report from Da Nang”, featuring his pictures and his personal account of the harrowing operation, was published two weeks later as a now-famous cover story in the April 16, 1965, issue of LIFE.

Photo: Man your battle stations: The crew chief of helicopter Yankee Papa 13, lance corporal James C. Farley, mans an M-60 machine gun during a mission near Da Nang, Vietnam on March 31, 1965. (Photo by Larry Burrows/Time & Life Pictures)

Ratko Mladic makes his first appearance at the International Criminal Tribunal on June 3, 2011 in The Hague, Netherlands. Ex-Bosnian Serb army leader Ratko Mladic will make his first appearance at The Hague war crimes tribunal after being declared fit to stand trial. Mladic was arrested a week ago after going into hiding for the past 16 years and is charged with atrocities committed during the Bosnian war. (Photo Serge Ligtenberg/Getty Images )

A police officer stands at a police cordon near the scene of a terror attack in London, U.K., on Sunday, June 4, 2017. A van swerved into Saturday-night crowds on London Bridge, before three men got out and went on a stabbing rampage through nearby bars. (Photo by Luke MacGregor/Bloomberg)

Chloe Goodman attending the Fantastic Beasts and Where to Find Them European Premiere at Leicester Square, London. (Photo by Ian West/PA Images via Getty Images)

Actor Howard Coggins performs during the Living Spits Beauty and the Beast comedy at the Bristol Old Vic on December 9, 2020 in Bristol, England. Living Spit stars Howard Coggins and Stu McLoughlin will perform Beauty and the Beast in a series of live broadcasts and on stage shows at the Old Vic from December 18. (Photo by Matthew Horwood/Getty Images)

Bavarian herdsmen and a herdswoman in traditional dresses drive their beasts on a road during the return of the cattle from the summer pastures in the mountains near Oberstaufen, Germany, Friday, September 9, 2016. (Photo by Matthias Schrader/AP Photo)

John Cox, far left, begins his recall campaign for California governor with “Tag”, a Kodiak brown bear, on Tuesday, May 4, 2021 in Sacramento. It was the first stop for his “Meet the Beast” bus tour. (Photo by Renee C. Byer/The Sacramento Bee via AP Photo)

Girls hold hands as they help each other wade through a flooded street after the passing of Hurricane Matthew in Les Cayes, Haiti, Thursday, October 6, 2016. Two days after the storm rampaged across the country's remote southwestern peninsula, authorities and aid workers still lack a clear picture of what they fear is the country's biggest disaster in years. (Photo by Dieu Nalio Chery/AP Photo)