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)

Three Chinese soldiers at the time of a civil war in China. (Photo by General Photographic Agency/Getty Images). 1922

A girl practices martial arts during a training at a school in Syrian opposition-held village of al-Jeineh, Syria on April 11, 2021. (Photo by Khalil Ashawi/Reuters)

American actress, singer, and songwriter Olivia Isabel Rodrigo arrives at the White House to promote the COVID-19 vaccine, Wednesday, July 14, 2021, in Washington. (Photo by Evan Vucci/AP Photo)

People wearing face masks to protect against the spread of the coronavirus walk on a crossing in Tokyo Tuesday, August 17, 2021. Japan’s coronavirus state of emergency will continue through Sept. 12 rather than finishing at the end of this month as initially planned, the government decided Monday. (Photo by Koji Sasahara/AP Photo)

A model presents a creation from the Christian Siriano Spring/Summer 2022 collection during New York Fashion Week at Gotham Hall in Manhattan, New York City, U.S., September 7, 2021. (Photo by Andrew Kelly/Reuters)

A model presents a creation by LARHHA during the Code'41 Andalusian Fashion Week at the Amphitheatre of Italica in Seville on March 21, 2021. (Photo by Cristina Quicler/AFP Photo)

Ukrainians attend an open military training for civilians on a training range in Kiev, Ukraine, 30 January 2022. According to a survey conducted by the Kiev International Institute of Sociology (KIIS) from December 2021, 50.2 percent of Ukrainians said they would resist in case of a Russian military intervention into their city, town or village. Every third respondent to the poll said they were ready to engage in armed resistance, and 21.7 percent said they were ready to participate in civil resistance actions. (Photo by Sergey Dolzhenko/EPA/EFE)