By 
By May of 1975, Saigon had fallen and the Khmer Rouge were working quickly to consolidate power in Kampuchea, then known as Cambodia. For the United States, the war in Vietnam was over, but in Southeast Asia political upheaval meant war still raged.
Unbeknownst to the 40-person crew of the civilian container ship SS Mayaguez, The Khmer Rouge had claimed a stretch of the Gulf of Thailand through which they planned to sail on their usual route. Also unbeknownst to them was the fact that in the two weeks since the fall of Saigon, the Khmer Rouge had been harassing and detaining foreign vessels sailing through the waters they claimed.
Thus it came as a surprise to the crew when, a little after 2 p.m. on May 12, 1975, Khmer Rouge swift boats fired a rocket-propelled grenade (RPG) across the bow of their ship, then boarded and took control. What followed was a domino effect of faulty decisions made without the right intelligence ending with the deaths of 41 American servicemen, the last 41 names added to the Vietnam Veterans Memorial Wall in Washington, D.C.
Within hours, the White House was aware of the situation and assembling the National Security Council to plan a response.
According to one Pentagon official, then-Secretary of State Henry Kissinger viewed the ship’s seizure as an opportunity to make a statement to the world in the aftermath of Vietnam: don’t mess with us.
Early on the morning on May 13, U.S. Navy P-3 Orion surveillance aircraft were on the move to locate the ship, while multiple Navy ships, Air Force security police, pararescuemen, and CH-53 helicopters, two units of Marines, and a bevy of fighter jets, bombers, and forward air control aircraft scrambled to assemble at an airfield in U-Tapao, Thailand.
In a harbinger of things to come, one CH-53 carrying 18 Air Force security police and a 5-man crew crashed en route to U-Tapao, killing all on board.
Aircraft continued tracking the Mayaguez until it reached the Cambodian island of Koh Tang, where the crew was disembarked onto small fishing and swift boats. After that, yet more confusion ensued. Surveillance saw people leaving the boats for the island, while other boats continued along the Cambodian coast. It was—wrongly—determined that at least some of the Mayaguez crew were taken to Koh Tang Island.
With that incorrect intelligence in hand, mission planners finalized their course of action. In simultaneous moves, the USS Henry Holt with a boarding party of Marines would forcibly retake the Mayaguez, while the rest of the Marines would conduct a two-pronged assault from two sides of the northern tip of Koh Tang: east beach and west beach.
According to Greg “Growth” Wilson, a Forward Air Control pilot with the 23rd Tactical Air Support Squadron (TASS), in his own write-up of the events, one planner requested TASS support for the mission, but Lt. Gen. John J. Burns, commander of the United States Support Activities Group, denied the request, deeming forward air controllers unnecessary, yet another mistake in an increasingly taut situation.
Perhaps the biggest error of all was the intelligence regarding exactly who was on Koh Tang. Not only was the Mayaguez crew on its way to mainland Cambodia for a cursory interrogation, but upwards of 200 veteran Khmer Rouge soldiers held the island with heavy weapons, entrenched fighting positions, bunkers, and tunnels. This information, for unclear reasons, was not shared with mission planners, who operated under the assumption that only about 20-30 “old men and farmers” occupied Koh Tang.
To make matters worse, the bulk of the Marine fighting force was composed of “boots,” Marines who had not experienced combat in Vietnam, many fresh out of boot camp. The majority of the combat-tested troops involved in the assault were the Air Force helicopter pilots and pararescuemen.
“Although the pilots were predominately 1st and 2nd [lieutenants], they were probably the most experienced El Tees [sic] on the planet,” wrote Wilson. That experience would prove vital in the coming battle.
A number of things happened simultaneously in the early morning of May 15. Shortly after 6 a.m. local time, the Khmer Rouge sent a radio broadcast that the Mayaguez crew, having been interrogated and in an effort to prevent an American assault, would be returned to their ship and allowed to contact the U.S. military. Minutes later, eight Air Force helicopters (operating under callsigns Knife and Jolly Green) took off with the first wave of Marines.
“When Khmer Rouge commander Em Som heard the distant thump of helicopter blades, he roused his men and sent them to their battle stations, where they locked and loaded antiaircraft guns, large machine guns, rocket propelled grenades, small arms, and waited for the Americans’ arrival in fortified bunkers,” wrote Peter Maguire for The Diplomat.
At the same time, the Holt comes alongside the Mayaguez and together with a team of Marines they conduct one of the few ship-to-ship hostile boardings since the Civil War. The Mayaguez is found empty.
By 6:30, Knife 23 was destroyed, after safely disembarking its Marines and crew, and Knife 31 was destroyed. 13 passengers and crewmen died in that crash, drown, or were shot by Khmer Rouge from the beach. The survivors waited two hours in the sea for rescue by the USS Wilson. A ground forward air controller used his survival radio to call in air strikes while he swam, up until the radio’s batteries died.
“Even before we got on the beach, a round hit us in the fuel tank,” Larry Barnett, a Marine veteran and survivor of the Knife 23 crash, said in an interview with Charles Rollet for The Phnom Pehn Post. “You feel the heat—a big bright orange glow.”
By 7 a.m., 109 Marines and five Airmen were on Koh Tang, however they were split between three locations: 20 Marines and the five Airmen on the east beach, the rest on the west beach, split into two groups by a jut of rocky land.
With two helicopters already down and more damaged too severely to continue flying without repairs, the young Marines found themselves in close combat with a more experienced and better prepared enemy force, with little hope of reinforcements arriving quickly.
“Most of us were 18 to 21-year-old young men, scared [expletive]-less, experiencing the throes of heavy combat for the first time,” wrote Al Bailey, a Marine veteran of Koh Tang, in his interview with The Diplomat.
Meanwhile, at 8:15 a.m. (Cambodian time), the White House announced skepticism of the Khmer Rouge promise to release the Mayaguez crew. The combat was to continue.
Between 9 and 11:50 a.m., more attempts were made to land reinforcements, but intense enemy fire prevented the helicopters from landing. A little after 9:30, a Navy P-3 Orion spotted a Khmer Rouge boat bearing the imprisoned crew on its way back to the Mayaguez. The crew was subsequently rescued and brought aboard the Wilson before returning to their own ship. The White House didn’t receive confirmation that the crew had been released until 11:30, and didn’t order an end to combat operations until just before noon. Unfortunately, extracting the Marines was no easy task.
Shortly after noon, helicopters are finally able to land and disembark approximately 100 Marine reinforcements in an attempt to get both beaches under enough control to mount a rescue of the embattled troops. Adding to the delays was the fact that so many helicopters were severely damaged, they needed time to be repaired enough to safely fly.
Throughout these early hours of combat, communication was hampered by the lack of a single on-scene forward air controller. Radio traffic is in chaos as Air Force, Naval aviation, and sea-to-land support from the three nearby ships attempt to coordinate air support for the Marines on the ground, according to George R. Dunham, U.S. Marines in Vietnam: The Bitter End, 1973-1975.
The withdrawal of ground forces didn’t begin in earnest until almost 5 p.m., after an Air Force forward air control (FAC) aircraft, an OV-10, callsign Nail 68, at last arrived and took singular control of the scene, along with three other OV-10’s.
“Prior to the FAC’s arrival, there was minimum coordination between ground and air forces, and the voice on the radio from above was never the same,” wrote Wilson, pilot of Nail 69, one of the OV-10’s in this wave. “Now, for the first time in over ten hours, there is command, control, communication, and continuity between air and ground forces, and it is Nail 68 that makes it happen.”
Helicopters began loading up groups of Marines, 50-60 at a time, double their usual combat load, and the Marines on the ground progressively shrank their defensive perimeters, slowly closing in until the last of them could leave.
One particularly harrowing rescue, a test of the pilot’s skill, involved Jolly Green 11’s rescue of the 25 troops isolated on the east beach. The Navy and Air Force provided a barrage of covering fire, but the wreckage of Knife 23 prevented the pilot from landing. Unwilling to leave anyone behind, the pilot dropped his helicopter into an extremely low hover, low enough for the Marines and Airmen to wade into the water and jump aboard.
The sun was setting quickly as round after round of helicopters extracted Marines, and more confusion ensued. Survivors were split between the Holt and the USS Coral Sea, and the highest ranking officer left on the west beach, Capt. James Davis, didn’t know every Marine who’d been dropped in that area. The Khmer Rouge were advancing, pressing the attack as fewer and fewer Marines were left to defend themselves. According to Matthew Burke, “The Truth about the Lost Marines of the Vietnam War’s Last Battle,” at one point Davis radioed to report that they were minutes away from being overrun.
Lance Cpl. Scott Standfast, one of the Marines who arrived with the second wave, took control of drawing their perimeter back, running from one fighting position to the next to tell the Marines to fall back. He set a three-man machine gun team to the far right of the Marine position. The team consisted of Lance Cpl. Joseph Hargrove, Pfc. Gary Hall, and Pvt. Danny Marshall.
When the last helicopter arrived, around 8 p.m., the Marines on board, including Standfast, insist there are still Marines on the ground. Davis, who had done a running check of the remaining fighting positions, insisted otherwise. The crew took Davis’ word, and they took off for the Holt.
About 20 minutes later, Air Force Staff Sgt. Robert Velie, flying overhead in the EC-130E Airborne Battlefield Command and Control Center, received a suspicious transmission from Koh Tang. An American voice asked when the next helicopter would be coming.
“We were told to lay cover fire and they’d come back for us,” Velie recalls the man saying, according to Burke.
Following protocol, Velie asked the voice to provide the authentication code, which the voice answered immediately. Hargrove, Hall, and Marshall were still on Koh Tang.
The Holt radioed the Marines and instructed them to swim out to sea, where they could be picked up, but the Marines refused. Not all of them could swim.
“I had to tell them that nobody was coming back for them,” said Velie in a Newsweek article quoted by The Diplomat.
Two gunships were on their way to barrage the island, so Velie instructed the Marines to take cover. After the barrage, Velie, then no one else, was able to raise the Marines on the radio. According to Burke, upon hearing this news, Davis volunteered to go back for them, but his request was denied. Too many aircraft had been damaged and commanders feared launching another failed assault.
On the night of May 15, SEAL Team 1’s Delta Platoon, commanded by Tom Coulter, was called in to breach the island to retrieve the American dead the following morning. The plan was to leaflet Koh Tang with papers informing them that an unarmed SEAL platoon would be there to retrieve the bodies, but Coulter shot this down, considering it a suicide mission.
When he was informed of the three Marines left alive, he advocated for a stealth assault of the island to rescue the men, but a conference call with the White House ended those hopes. The risk was too high, according to Coulter’s recollection of the call.
Throughout the morning of May 16, the Wilson circled the island while surveillance planes crisscrossed the terrain overhead, search for the three Marines, but they found no sign of them. At 10 a.m., the ship was ordered to depart. Hargrove, Hall, and Marshall were left for dead.
They were not dead.
The Khmer Rouge fighters emerged from the jungle once the ship left and began combing the beach, shocked to find not only bodies, but piles of military equipment abandoned where it was dropped.
“I didn’t count how many there were, but I remember dragging five or six bodies myself [to the water]. If we’d known the Americans would have come back some day to look for the bodies, we would have put all the bodies in one easy-to-find place,” said Mao Ran, a Khmer Rouge veteran of the battle in an interview with The Diplomat. They tied the bodies to a row boat and dropped them in the sea.
Over the next few days, the Khmers noticed things—odd boot prints in the sand and missing food.
Em Son, commander of the Khmers on Koh Tang, has claimed that he personally executed Hargrove, then had his men buried him beneath a mango tree. Hall and Marshall, he claims, were captured alive and taken to the Cambodian mainland, where they, too, were executed.
Burke wrote, “The Communists held the Marines at a temple converted into a prison, but eventually, Son says, the guards marched the two Marines out to the beach, where they beat them to death.”
In the end, 41 Americans died attempting to rescue the Mayaguez crew.
Since the 1990’s, American investigators have found and identified the remains of 13 Americans who died on Koh Tang. In 2016, Hall’s ID card and multiple personal items were found on the island.
Hargrove, Hall, and Marshall were not declared “Killed in Action (Body Not Recovered)” until July 21, 1976.
Back home, Americans celebrated the successful rescue of the Mayaguez crew, largely unaware of the bungled assault on Koh Tang or the lives lost there.
“Decisions were driven by the desire to do something and to do it as quickly as possible,” wrote Dunham. “Unfortunately, the frontline Marine was the recipient of the results of poor decision-making.”
The surviving Marine veterans of the battle applied to have the Vietnam Service medal added to their military records in 2016. They were denied.
The 41 dead—whose names were added to the Vietnam Veterans Memorial Wall—include 25 Air Force pilots and crew, two Navy corpsmen, and 14 Marines.