Forty-five years ago the United States military fought its last battle of the Indochinese wars, soon after the Khmer Rouge began sacking Phnom Penh and illegally seized the SS Mayaguez, sailing through the Gulf of Siam.
Washington launched a rescue operation, sending in the Marines. They recaptured the U.S. merchant vessel and attacked the island of Koh Tang, prompting Pol Pot to release the hostages.
But resistance on the island was strong. Between May 12 and 15, 1975, helicopters were downed and marines fought a pitched battle before evacuating. In all, 41 U.S. servicemen were killed in an operation which rescued 40 people.
In full: https://thediplomat.com/2020/05/the-mayaguez-honoring-the-fallen-and-remembering-the-survivors/