A participant runs in high-heels as she competes in the Stiletto Run in Bucharest June 14, 2014. The annual 50 metres race requires participants to wear high-heels that are at least 7cm tall. (Photo by Bogdan Cristel/Reuters)

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 three-month-old Sumatran tiger cub named “Bandar” shows his displeasure after being dunked in the tiger exhibit moat for a swim reliability test at the National Zoo in Washington, on November 6, 2013. All cubs born at the zoo must take a swim test before being allowed to roam in the exhibit. Bandar passed his test. (Photo by Manuel Balce Ceneta/Associated Press)

Karis, an eleven week old lion cub, plays in fallen leaves brushed up by keepers in her enclosure at Blair Drummond Safari Park, near Stirling, Scotland, on November 20, 2013. (Photo by Andrew Milligan/PA Wire)

Sarah Paulson and Amanda Peet arrive at the 20th annual Screen Actors Guild Awards. (Photo by Jordan Strauss/AP Photo/Invision)

A fisherman sorts his net next to the 37-meter-long “KAWS:HOLIDAY Companion” inflatable sculpture in Tsing Yi, Hong Kong, China, 21 March 2019. KAWS:HOLIDAY, made by US artist and designer Brian Donnelly known professionally as Kaws, will be displayed in Hong Kong's Victoria Harbour from 22 to 31 March 2019. (Photo by Jerome Favre/EPA/EFE)

Members of carnival marching bands in costumes parade through the streets during the so-called “Morgestraich” carnival parade in Basel, Switzerland, on Monday, early 07 March 2022. The traditional “Morgenstraich” parade with colorful lanterns and revelers in traditional costumes is starting early morning at 4 a.m. and marks the kick-off for the Basel carnival. It was not held in its usual form in the past two years because of the measures against the Covid-19 pandemic. (Photo by Georgios Kefalas/EPA/EFE)