 The fighting had no sooner died down around Saigon than U.S. forces in Quảng Tín Province suffered what was , without doubt , the most serious American defeat of the war . On 10 May , two regiments of the 2nd PAVN Division attacked Kham Duc , the last Special Forces border surveillance camp in I Corps . 1 @,@ 800 U.S. and South Vietnamese troops were isolated and under intense attack when MACV made the decision to avoid a situation reminiscent of that at Khe Sanh . Kham Duc was evacuated by air while under fire , and abandoned to the North Vietnamese . 
