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 Tuesday, July 14, 2015, photo, Phoe Thaw, center, a member of the White New Blood lethwei fighters club, a Myanmar traditional martial-arts club which practices a rough form of kickboxing, stretches during a practice session in their gym on a street in Oakalarpa, north of Yangon, Myanmar. Three of the club's members competed this summer on a stage a world away from the street gym: a mixed-martial-arts “One Championship” event broadcast globally on cable television networks, where fighters could receive $1,000 for each fight, according to coach Myint Zaw who started the traditional fighters' club 15 years ago. (Photo by Gemunu Amarasinghe/AP Photo)

In this May 31, 2016 photo, pieces of watermelon litter the trash area of the Coche public market in Caracas, Venezuela. Staples such as corn flour and cooking oil are subsidized, costing pennies at the strongest of two official exchange rates. But fruit and vegetables have become an unaffordable luxury for many Venezuelan families. (Photo by Fernando Llano/AP Photo)

Model Bella Hadid celebrates her 20th birthday with her mother Yolanda Foster, The Weeknd and Shanina Shaik at Up & Down in New York City, NY on October 10, 2016. (Photo by TheStewartofNY/Splash News)

People visit the autonomous urban concept car Renault EZ-GO during the first press day of the Geneva International Motor Show on March 6, 2018 in Geneva. The show opens to the public on March 8 and runs through March 18. (Photo by Fabrice Coffrini/AFP Photo)

Fishermen collect their catch from a net at Dojran Lake, Macedonia, January 4, 2017. Fish from the lake is a traditional food for locals for orthodox Christmas eve, which falls on January 6. The lake faced sustainability issues during the 1990s due to drought and excessive use of its water but has since recovered after measures were taken to replenish and sustain water levels, according to local media. Dojran Lake is one of the three natural lakes in Macedonia, and also the warmest. It is said it is also the richest lake in fish in Europe. (Photo by Ognen Teofilovski/Reuters)

A child working at Ship breaking yard in Chittagong, Bangladesh on November 14, 2014. (Photo by Pascal Mannaerts/Alamy Stock Photo)

A girl uses a mattress as a raft during the flood after the Xepian-Xe Nam Noy hydropower dam collapsed in Attapeu province, Laos July 26, 2018. At least 26 people were killed and over 3,000 people stranded after a hydroelectric dam built collapsed in southeastern Laos, destroying thousands of homes and leaving an unknown number of dead. (Photo by Soe Zeya Tun/Reuters)