In July 1944 , U.S. Marines invaded the Mariana Islands .
As soon as West Field , Tinian , was readied in May 1945 , the group flew to West Field and continued the Air Offensive against Japan .
In July 1944 , U.S. Marines invaded the Mariana Islands and as soon as West Field , Tinian , was readied in May 1945 , the group flew to West Field and continued the Air Offensive against Japan .