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)

“Erwin Olaf is a Dutch photographer. Olaf is most famous for his commercial and personal work. His work has received many awards and he has held exhibitions around the world”. – Wikipedia. Photo: «Berlin» Project. Porträt 01, April, 22, 2012. (Photo by Erwin Olaf/Hasted Kraeutler Gallery)

Villagers from the Porto Novo community load into their canoes arapaima or pirarucu, the largest freshwater fish species in South America and one of the largest in the world, while fishing in Poco Fundo lake along a branch of the Solimoes river, one of the main tributaries of the Amazon, in the Mamiraua nature reserve near Fonte Boa about 600 km (373 miles) west of Manaus, November 26, 2013. Catching the arapaima, a fish that is sought after for its meat and is considered by biologists to be a living fossil, is only allowed once a year by Brazil's environmental protection agency. The minimum size allowed for a fisherman to keep an arapaima is 1.5 meters (4.9 feet). (Photo by Bruno Kelly/Reuters)

“Jallikattu is a bull taming sport played in Tamil Nadu as a part of Pongal celebrations on Mattu Pongal day. Annually, jallikattu is held from January to July, played first in world-famous Palamedu, near Madurai on January 15 followed by “Alanganallur-jallikattu” in Alanganallur, near Madurai on 16 January. There is a specific breed of cattle bred for this purpose known as Jellicut and from the place of a big breeder Pulikulam”. – Wikipedia. Photo: Bull tamers try to control a bull during the bull-taming sport called Jallikattu, in Palamedu, about 575 kilometers (359 miles) south of Chennai, India, Tuesday, January 15, 2013. (Photo by Arun Sankar K./AP Photo)

A chevrotain or mouse deer feeds in its enclosure at Zurich Zoo, Zurich, Switzerland, October 17, 2012. (Photo by Patrick B. Kraemer/AP)

Gentoo penguins watching Christmas films at the Sea Life London aquarium on November 30, 2020. The attraction has installed two TVs, showing festive films, outside the penguin enclosure to prepare them for the stimulation of guests returning on Wednesday after the UK’s lockdown is lifted. (Photo by Yui Mok/PA Images via Getty Images)

People wearing face masks walk through Ginza area on December 27, 2020 in Tokyo, Japan. Japan announced it will close its borders to non-resident foreign nationals from tomorrow until the end of January after two people were discovered to be infected with a new strain of Covid-19 coronavirus that has begun spreading around the world. The country is also grappling with a surge in coronavirus infections, with Tokyo reporting 708 cases today. To date, Japan has recorded 218,453 infections, 3,052 deaths and 3,052 recoveries from the virus. (Photo by Yuichi Yamazaki/Getty Images)

Vietnamese dentist Tran Phuong Thao and her husband Tran Minh Hieu wearing protective masks, kiss at their wedding ceremony during the coronavirus disease (COVID-19) outbreak in Hanoi, Vietnam on January 28, 2021. (Photo by Kham via Reuters)