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)

In this handout image provided by Carnival Australia, captain of the Queen Mary 2 Christopher Rynd poses on the desk of the Queen Mary 2 on February 8, 2012 in Perth, Australia. (Photo by James Morgan/Carnival Australia via Getty Images)

Private Wallace Tratford arrives home on leave, Drouin, Victoria, ca. 1944. A.I.F. Private Wallace Tratford, son of 1st Constable James Tratford, Drouin's only policeman (responsible for area of 105 square miles; 3,000 people), arrives home on his first leave from New Guinea battlefronts since he was married.

English fashion model Daisy Lowe seen at LFW s/s 2018: Off-White x Mytheresa.com – intimate dinner at St John Bar & Restaurant during London Fashion Week September 2017 on September 17, 2017 in London, England. (Photo by MagicMoments UK)

An Atlantic seal pup lies amongst the rocks at St Martin's Haven, Pembrokeshire, Wales, Britain October 8, 2018. Seal pups are born with fluffy white non-waterproof coats which they moult out in their fourth week. (Photo by Rebecca Naden/Reuters)

Students wearing mask hold hands to surround the St. Stephen's Girls' College in Hong Kong, Monday, September 9, 2019. Thousands of demonstrators in Hong Kong urged President Donald Trump to “liberate” the semiautonomous Chinese territory during a peaceful march to the U.S. Consulate on Sunday, but violence broke out later in the business and retail district as police fired tear gas after protesters vandalized subway stations, set fires and blocked traffic. (Photo by Kin Cheung/AP Photo)

A nurse bows to the life size statue of Pope Francis as her friend takes a photograph at the St.Louis hospital in Bangkok, Thailand, Tuesday, November 19, 2019. Pope Francis arrives in Thailand on Wednesday for the first visit here by the head of the Roman Catholic Church since St. John Paul II in 1984. (Photo by Manish Swarup/AP Photo)

A nurse at St. Joseph's Hospital wears a unique mask as the hospital celebrates the release of a COVID-19 patient after 45 days in their care during the outbreak of the coronavirus disease (COVID-19) in Orange, California, U.S., May 5, 2020. (Photo by Mike Blake/Reuters)