PAVN (People's Army of Vietnam) forces surrounded and captured Hue on March 26, 1975. The ARVN (Army of the Republic of Vietnam) defenses collapsed quickly at the start of the spring offensive. They had been ordered to retreat towards Da Nang, but the disorganized rout and the destruction of the bridge between Hue and Da Nang left many surrounded in Hue, where they surrendered with their US-made equipment. The US had, unfortunately, organized and equipped the ARVN in the US model, mechanized with emphasis on overwhelming firepower. South Vietnam lacked the industrial capacity to maintain and supply such a force. Nixon had promised support in the case of a major breach of the peace accords, but he had already resigned over the Watergate scandal, and Congress chose not to provide assistance.

So, yes, the equipment was captured on that day, but not from US troops. The last US combat units departed South Vietnam in February-March, 1973, but left much of their equipment to the ARVN.