The first crisis was the "Mayaguez" incident. In May 1975, shortly after the fall of Saigon and the Khmer Rouge conquest of Cambodia, Cambodians seized the American merchant ship "Mayaguez" in international waters. Ford dispatched Marines to rescue the crew, but the Marines landed on the wrong island and met unexpectedly stiff resistance just as, unknown to the U.S., the "Mayaguez" sailors were being released. In the operation, two military transport helicopters carrying the Marines for the assault operation were shot down, and 41 U.S. servicemen were killed and 50 wounded, while approximately 60 Khmer Rouge soldiers were killed. Despite the American losses, the operation was seen as a success in the United States, and Ford enjoyed an 11-point boost in his approval ratings in the aftermath. The Americans killed during the operation became the last to have their names inscribed on the Vietnam Veterans Memorial wall in Washington, D.C.