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 Lion-Tailed macaque holds a big block of ice with a mix of frozen vegetables and fruit at the zoo in Leipzig, central Germany, Friday, July 19, 2013. Weather forecasts predict sunny weather and warm temperatures for Germany in the next few days. (Photo by Jens Meyer/AP Photo)

In this July 23, 2013 photo, sand fills an abandoned house in Kolmanskop, Namibia. Kolmanskop, was a diamond mining town south of Namibia, build in 1908 and deserted in 1956. SInce then, the desert slowly reclaims its territory, with sand invading the buildings where 350 German colonists and more than 800 local workers lived during its hay-days of the 1920s. (Photo by Jerome Delay/AP Photo)

Social distancing signs are pictured as models wear protective face masks before the show of designer Andres Sarda during the Mercedes Benz Fashion Week amid the coronavirus disease (COVID-19) outbreak in Madrid, Spain, September 10, 2020. (Photo by Sergio Perez/Reuters)

Jordan Spence and Dawson Stallworth watch waves come ashore as Hurricane Sally approaches in Orange Beach, Alabama, U.S., September 15, 2020. (Photo by Jonathan Bachman/Reuters)

People gather to mourn the death of soccer legend Diego Maradona, outside the Diego Armando Maradona stadium, in Buenos Aires, Argentina on November 25, 2020. Millions of fans paid tribute and Argentina was plunged into mourning on November 25 as Maradona, one of the greatest footballers of all time, died aged 60 after years of drug and alcohol problems. (Photo by Martin Villar/Reuters)

A group of girls hit the town in York, United Kingdom on December 30, 2020. Revellers hit the streets for a final drink before being plunged into Tier 4 lockdown. (Photo by Nb press ltd)

Alexandr Kudlay, 33, and Viktoria Pustovitova, 28, have breakfast in their apartment in Kharkiv, Ukraine on March 5, 2021. Tired of occasional break-ups, this Ukrainian couple found an unusual solution to stay inseparable. On St. Valentine's Day, they decided to handcuff their hands together for three months and began documenting their experience on social media. (Photo by Gleb Garanich/Reuters)