Germans estimated at no more than 100 men. Battle On the early morning of 1 September 1939, Schleswig-Holstein fired a broadside at the Polish garrison. That salvo's time has been variously stated as 04:45, 04:47, or 04:48. Polish historian Jarosław Tuliszka explains that 04:45 was the planned time, 04:47 was the time the order was given by Kleikamp and 04:48 was the time the guns actually fired. Shortly after, on Westerplatte, Sucharski radioed the nearby Polish military base on the Hel Peninsula, "SOS: I'm under fire." The battleship's initial bombardment was not very successful, failing to inflict a single casualty among the defenders, as due to the battleship's proximity to its target its heavier shells did not have time to arm and did not explode upon impact. Eight minutes later Henningsen's marines from the Schleswig-Holstein, who had disembarked two hours earlier on the eastern side of the peninsula, advanced, expecting an easy victory over the Poles. However, after crossing the artillery-breached brick wall at the border, advancing about , and engaging the Polish Prom outpost, the Germans ran into an ambush. They found themselves in a kill zone of Polish crossfire from concealed firing positions, while barbed-wire entanglements impeded their movements. Around 05:15, the field gun, commanded by Pająk, opened intense fire on the advancing Germans, firing 28 rounds and knocking out several machine-gun nests atop warehouses across the harbour canal. Meanwhile, the German infantry was also shelled by the Polish mortars, and even the battleship itself was targeted by the Polish 37 mm guns. Around that time, the Poles also repulsed an attempt by a small maritime unit of the Danzig Police to land on the western side of the depot. In that initial engagement, Poles sustained two casualties, and a Polish soldier, Staff Sergeant Wojciech Najsarek, was killed by machine-gun fire. Najsarek has been described as the first Polish combat casualty of the battle and perhaps of the war. At 06:22, the German marines frantically radioed the battleship that they had sustained heavy losses and were withdrawing. Casualties were approximately fifty Germans and eight Poles, mostly wounded. A longer bombardment from the battleship, lasting from 07:40 to 08:55, preceded a second attack and succeeded at knocking out the Polish field gun. The Germans assaulted again from 08:35 to 12:30 but encountered mines, felled trees, barbed wire and intense fire. By noon, when the Germans retreated, Henningsen had been