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)

A male deer barks at dawn during the annual deer rutting season at Richmond Park in London, Britain, October 9, 2016. (Photo by Toby Melville/Reuters)

A woman holds Kalashnikov assault rifle during a training session with members of the Georgian Legion, a paramilitary unit formed mainly by ethnic Georgian volunteers to fight against Russian forces in Ukraine in 2014, in Kyiv, Ukraine, Saturday, February 19, 2022. Separatist leaders in eastern Ukraine have ordered a full military mobilization amid growing fears in the West that Russia is planning to invade the neighboring country. The announcement on Saturday came amid a spike in violence along the line of contact between Ukrainian forces and the pro-Russia rebels in recent days. (Photo by Efrem Lukatsky/AP Photo)

Figurative lanterns for Lunar New Year hang over a road to mark the upcoming Year of the Ox in Singapore on January 19, 2021. (Photo by Roslan Rahman/AFP Photo)

A model wears a creation as part of the Valentino Haute Couture Spring-Summer 2023 collection presented in Paris, Wednesday, January 25, 2023. (Photo by Lewis Joly/AP Photo)

Maya Goldstein, 7 marches in the Capital Pride Parade in Washington, D.C. on June 10, 2023. (Photo by Amanda Andrade-Rhoades for The Washington Post)

Charlotte FC goalkeeper Kristijan Kahlina deflects a shot by Inter Miami forward Leonardo Campana during the second half of an MLS soccer match, Wednesday, October 18, 2023, in Fort Lauderdale, Fla. (Photo by Rebecca Blackwell/AP Photo)

An asylum-seeking migrant child from Honduras reacts as disembarking an inflatable raft after crossing the Rio Grande river into the United States from Mexico in Roma, Texas, U.S., June 8, 2021. (Photo by Go Nakamura/Reuters)