As early as 18 February, PAVN forces had begun attacks by fire on bases Ranger North and South. A UH-1H medevac helicopter from the 237th Medical Detachment was hit by PAVN fire and crash-landed at Ranger North: two of its crew were rescued by another helicopter while the crew chief Sp4c. Dennis J. Fuji was unable to reach the rescue helicopter due to fire and stayed at the base to assist the Rangers, providing medical assistance and directing US airstrikes. On 19 February, the attacks commenced against Ranger North conducted by the 102nd Regiment, 308th Division, supported by PT-76 and T-54 tanks. The ARVN held on tenaciously throughout the night supported by gunships and flareships. President Thiệu, oblivious to the previous nights attacks, and who was visiting I Corps headquarters at the time, advised General Lãm to postpone the advance on Tchepone and to shift the focus of the operation toward the southwest. Despite 32 tactical airstrikes since the morning, by the afternoon of the 20th, the 39th Ranger Battalion had been reduced from 500 to 323 men and aerial reconnaissance indicated that their position was surrounded by 4–500 PAVN and its commander ordered a retreat toward Ranger South, 6km away. Fuji and several Rangers were evacuated by helicopter, but it was hit by PAVN fire and autorotated onto Ranger South. The crew was rescued but Fuji was again stranded on the ground. Only 199 survivors reached Ranger South by nightfall, with only 109 fit for combat, while 178 were dead or missing. The U.S estimated 639 PAVN troops were killed during the battle.