 The ARVN regimental headquarters, monitoring the North Vietnamese radio net at that time, heard the PAVN commander express surprised disbelief at losing his tanks to cannon he could not see.The steady deterioration of the tactical situation around Đông Hà was arrested by the arrival of the 1st Armor Brigade headquarters.Although the brigade headquarters had been in the area solely to monitor the 20th Tank Regiment's training exercise, it was a well-trained organization, possessing the armored vehicles and radios needed by General Giai to establish control of the scattered forces and direct the defense he hoped to establish at Đông Hà.