An animatronic polar bear visits the London Underground on January 23, 2015, to mark the launch of Fortitude, Sky Atlantic&Otilde's new drama starring Stanley Tucci, Michael Gambon and Christopher Ecclestone, which premieres on Thursday 29th January at 9pm. A team of 19 Hollywood prop specialists spent six weeks designing and building the realistic replica animal with six to eight people working on the costume at any one time, using over 60 different materials. (Photo by David Parry/PA Wire)

Miss World 2013, Megan Young of the Philippines, poses during a publicity launch near to Big Ben and the Houses of Parliament in central London November 25, 2014. The final of the 2014 edition of the pageant will take place in London on December 14. (Photo by Toby Melville/Reuters)

A model presents a creation during the pushBUTTON catwalk show at London Fashion Week Women's A/W19 in London, Britain February 19, 2019. (Photo by Henry Nicholls/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)

Passengers ride an articulated bus known as a “bendy bus” on December 9, 2011 in London, England. The last remaining bendy bus will go out of service at midnight. London Mayor Boris Johnson called them cumbersome and pledged to remove them. 500 new buses are being introduced as replacements. (Photo by Peter Macdiarmid/Getty Images)

A cameraman films “Diana And Callisto” (circa 1556-59) oil painting by Venetian artist Titian as it goes on display for the first time at the National Gallery on March 1, 2012 in London, England.(Photo by Dan Kitwood/Getty Images)

A five-month-old female slender loris waits to be given her first health check by the veterinary team at London Zoo on July 21, 2011 in London, England. Two female baby slender lorises, who are yet to be named, were given health checks, their s*x determined and micro-chipped. Slender Loris is the common name for the strepsirrhine primates who are nocturnal and originate from India, Sri Lanka, and southeast Asia. London Zoo supports conservation of lorises in Sri Lanka, where populations are thought to be under threat from deforestation. (Photo by Christopher Furlong/Getty Images)

Alejandro Simon of Spain prepares to serve during their Preliminary Phase Pool E match against Canada during the VISA FIVB Beach Volleyball International at Horse Guards Parade on August 10, 2011 in London, England. (Photo by Scott Heavey/Getty Images)