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)

Performers dressed like Stormtroopers dance during “The Empire Strips Back: A Star Wars Burlesque Parody” in Los Angeles, California, U.S., June 1, 2018. (Photo by Mario Anzuoni/Reuters)

A mahout watches the Thai animation movie Kan Kluay with his elephant in Ayuthaya province, about 80km (49 miles) north of Bangkok June 5, 2006. The movie tells the story of a young Thai wild elephant who, while looking for his father, becomes the war elephant of the Thai King fighting against Burma and restored Thailand's ancient Ayuthaya empire that existed about 400 years ago. (Photo by Sukree Sukplang/Reuters)

In this Thursday, July 19, 2018, photo, a Syrian shopkeeper spraying water as waits for customers at the Hamadiyah market, named after the 34th Sultan of the Ottoman Empire Abdul Hamid II, in the Old City of Damascus, Syria. The celebratory mood in government-controlled areas stems from successive military advances in the past year and an impression that President Bashar Assad, with massive support by unwavering allies Russia and Iran, has won the war or at least militarily defeated the opposition trying to topple him. (Photo by Hassan Ammar/AP Photo)

Indian wrestlers Rashid Anwar (left) and Ajaib Singh in a training bout at Lane's Club in Baker Street London before the Empire Games, 19th July 1934. (Photo by Keystone/Hulton Archive/Getty Images)

“Pearl Harbor, known to Hawaiians as Puʻuloa, is a lagoon harbor on the island of Oʻahu, Hawaiʻi, west of Honolulu. Much of the harbor and surrounding lands is a United States Navy deep-water naval base. It is also the headquarters of the U.S. Pacific Fleet. The attack on Pearl Harbor by the Empire of Japan on December 7, 1941, brought the United States into World War II”. – Wikipedia

Photo: Women fire fighters directing a hose after the Japanese attack on the US naval base at Pearl Harbour (Pearl Harbor). (Photo by Three Lions)

“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

“The Spanish Civil War (The Crusade among Nationalists, Fourth Carlist War among Carlists, The Rebellion or Uprising among Republicans) was a major conflict fought in Spain from 17 July 1936 to 1 April 1939. An estimated total of 500,000 people lost their lives as a consequence of the War”. – Wikipedia. Photo: Actors take part in a re-enactment of the “Battle of Areces” that took place during the Spanish Civil War, in Grullos, north of Spain, September 14, 2013. The re-enactment of the historic 1937 battle was organised by the Frente del Nalon Association. (Photo by Eloy Alonso/Reuters)