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)

This photo released by the Cleveland Animal Protective League shows Lurleen, the nursing mother and Noland the puppy snuggling up Wednesday, June 19, 2013, in Cleveland. Lurleen already is caring for four newborn kittens and now is nursing the orphaned week-old pit bull puppy in Cleveland. (Photo by AP Photo/Cleveland Animal Protective League)

A German special anti-tank gun is ready to fire during the army maneuvers in Silesia, Poland, on September 22, 1928. (Photo by AP Photo)

His own space suit, with oxygen tank, doesn't make Barney the monkey any happier as he and actor Adam West view the situation in their space capsule in Hollywood on January 24, 1964. Barney, a South American woolly monkey, is blasted into space with West, as an astronaut, in a new movie, “Robinson Crusoe on Mars”. (Photo by AP Photo)

A man in a Donald Trump mask joins hundreds of other protesters and activists as they march during a demonstration near a midtown hotel which is hosting a black-tie fund-raiser for the state Republican Party on April 14, 2016 in New York City. (Photo by Spencer Platt/Getty Images)

A man cries over the body of his girlfriend, who was killed by shelling in the Kalininsky district of Donetsk, territory under control of the pro-Russian Government of the Donetsk People's Republic in eastern Ukraine, Thursday, June 9, 2022, during the Russian invasion. (Photo by Alexei Alexandrov/AP Photo)

Children play in the Crown Fountain at Millennium Park in Chicago, Wednesday, June 29, 2022. (Photo by Nam Y. Huh/AP Photo)

Mahsa Kadkhoda #11 of Team Iran spikes the ball during their semi-final round match against Team Chinese Taipei on day seven of the AVC Cup For Women at PhilSports Arena on August 28, 2022 in Pasig, Philippines. (Photo by Ezra Acayan/Getty Images)