StG 3 supported the DAK in the Battle of Bir Hakeim and Battle of Gazala. Sigel's airmen flew 1,400 Sorties against Bir Hakeim. I./StG 3 reported 10 or 11 Ju 87s destroyed over Gazala from 26 May to 4 June. On 3 June I./StG 3 lost five destroyed and one damaged. The following day it lost its commander Heinrich Eppen killed by South African Air Force fighters. II./StG 3 lost another aircraft over Bir Hacheim fortress. StG 3 lost five destroyed or damaged on this date—two were certainly destroyed and one severely damaged. Seven men were killed, four wounded with one of the latter captured. Eppen was replaced by Hauptmann Martin Mossdorf on 5 June. StG 3 losses may have been as high as 14 Ju 87 in the first week over Bir Hacheim but the dive bombers were instrumental in the capture of the fort—in the last dive bombing raid 124 Ju 87s were sent against the Allied garrison. In the first week 100 attacks were carried out; on 9 June two waves of 100 Ju 87s dive bombed the fortress.