The Mayagüez incident with the Khmer Rouge, which ended on May 15, 1975, marked the last official battle of the 2nd Battalion, 9th Marines in the Vietnam War. The unit deployment program was put into practice in February 1979, and 2nd Battalion, 9th Marines became the first battalion to rotate to the United States. A total of 18 Marines were killed on the last day of the SS Mayaguez rescue operation. They are the last Marines listed on the timeline of the Vietnam Veterans Memorial located in Washington, D.C.