 On 19 August, after 60 Arclight strikes 2nd Battalion 1st Marines (2/1) assaulted into three LZs in the Trung Son region of the southern DMZ, 5 km north of Con Thien.Supported by a platoon of tanks from 3rd Tank Battalion, 2/1 swept the area but found no evidence of use by VPAF helicopters.During the extraction one CH-46 Sea Knight was destroyed by a command detonated mine, killing 4 Marines.