An assault on Saipan was commenced on June 15, 1944, and 4th Marine Division was tasked with the capture of Aslito airfield in the southern end of the island and advance north along the east coast. The Fourth Division assaulted Hill 500, an enemy strongpoint in southern part of Saipan, on June 20 and finished his advance with the capturing of Marpi Point Field on July 9, when an island was declared secured.