While the 1st SA and 50th Divisions were preparing for their withdrawal on the Via Balbia, Axis forces were wreaking havoc on the escarpment amongst Allied forces and Rommel dictated his 170mm guns to open fire from the escarpment down onto the Via Balbia as the South Africans and British were destroying their ammunition dumps in the Gazala Line Rommel tasked 15th and 21st Panzer with breaking north and severing the Via Balbia close to Elwet et Tamar, cutting off the two Divisions to the west. With the road being unable to accommodate two divisions, elements of the 50th Division broke out in a south westerly direction in a wide sweep eventually turning back east towards the Allied lines. The South Africans withdrew to series of defensive boxes at Williams Post, Best Post, "Point 187," Commonwealth Keep and then Acroma. The 21st and 15th Panzer attacks forced the 1st SA Division to fight a rearguard action and to withdraw through each of the respective boxes well into the night. Chased by Axis tanks, driving east on the Via Balbia, the first elements reached Tobruk during the night of 13/14 June. The division was now spread out between the original Gazala defences and Tobruk, as each element tried to make their way east.