Marines of the Baltic Fleet forces of the Russian Navy train in the zone of obstacles during military exercises at the Khmelevka firing ground in the Kaliningrad region, Russia on November 24, 2021. (Photo by Vitaly Nevar/Reuters)

Party-loving Brits headed out to enjoy the first weekend of indoor drinking in months; many – like these lasses in Liverpool on May 22, 2021 – were keen to make up for lost time. (Photo by London News Pictures)

One woman was pictured sitting bare foot on a pavement in Leeds in the northern English county of Yorkshire on May 30, 2021. With the sun streaming down, Brits have been taking full advantage of the three-day weekend by packing out pub gardens and lining up the beers at bars. (Photo by Nb press ltd)

Pakistani boys jump in the water to cool off in a pond to beat the heat wave continues in Larkana, Pakistan, 26 June 2021. Pakistan's Meteorological Department (PMD) said the weather in the city will remain hot and humid for the next three days. (Photo by Waqar Hussain/EPA/EFE)

Firls attend Sunday Mass at Sacre-Coeur church, in Port-au-Prince, Sunday, July 11, 2021, four days after President Jovenel Moise was assassinated in his home. (Photo by Joseph Odelyn/AP Photo)

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)

Gunfire erupted at a Denver pot celebration Saturday, injuring two people and scattering a crowd of thousands who had gathered for the first 4/20 counterculture holiday since the state legalized marijuana... Photo: A woman smokes a large marijuana joint at the Vancouver Art Gallery during the annual 4/20 day, which promotes the use of marijuana, in Vancouver, British Columbia April 20, 2013. (Photo by Ben Nelms/Reuters)

Three prostitutes lean out of a window in Santiago, Chile, in an attempt to entice customers inside, circa 1950. (Photo by Three Lions/Getty Images)