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 woman dressed up as a zombie takes part in a zombie walk in the Gaslamp Quarter during the Comic Con International convention in San Diego, California July 13, 2012. (Photo by Mario Anzuoni/Reuters)

Model airplane enthusiasts take part in an event at a model airplane field in Mamak district of Ankara, Turkey on December 30, 2021. Model airplane enthusiasts, each owns different sizes and types of aircrafts, have the opportunity to have fun while training. Weekend meetups also give them an opportunity to help each other on technical issues. (Photo by Dogukan Keskinkilic/Anadolu Agency via Getty Images)

Activists from the animal rights group PETA wearing bikinis and crocodile masks assist each other outside a store of the French fashion label Hermes in Sydney on March 4, 2021, as they protest against their use of crocodile skins and the recent purchases by Hermes and LVMH of crocodile farms in Australia's Northern Territory. (Photo by David Gray/AFP Photo)

A woman holds Kalashnikov assault rifle during a training session with members of the Georgian Legion, a paramilitary unit formed mainly by ethnic Georgian volunteers to fight against Russian forces in Ukraine in 2014, in Kyiv, Ukraine, Saturday, February 19, 2022. Separatist leaders in eastern Ukraine have ordered a full military mobilization amid growing fears in the West that Russia is planning to invade the neighboring country. The announcement on Saturday came amid a spike in violence along the line of contact between Ukrainian forces and the pro-Russia rebels in recent days. (Photo by Efrem Lukatsky/AP Photo)

Alexia Putellas of FC Barcelona celebrates victory with fans following the UEFA Women's Champions League Quarter Final Second Leg match between FC Barcelona and Real Madrid at Camp Nou on March 30, 2022 in Barcelona, Spain. (Photo by Alex Caparros – UEFA/UEFA via Getty Images)

Police officers introduce a litter of golden retriever puppies to be trained as police dogs during a ceremony at the National Police Academy in La Paz, Bolivia, Monday, August 16, 2021, the date of the feast day for Saint Roch, considered the patron saint of dogs, among other things. (Photo by Juan Karita/AP Photo)

A Palestinian waves fireworks on the last day of the holy month of Ramadan in Khan Yunis in the southern Gaza Strip on May 1, 2022. (Photo by Yousef Masoud/SOPA Images/Rex Features/Shutterstock)