Walton Walker
As North Korean troops moved steadily down Korea, outnumbered American troops retreated south. General Walton Walker decided to build a perimeter defense to shelter Pusan, the key port. As the Eighth United States Army built up its defenses, Communist troops massed across the Naktong River for a thrust at Taegu, less than 100 miles north of Pusan. To lessen this threat, O'Donnell led 98 B-29s on a bombing mission near Waegwan. During this period of temporary duty he retained command of the 15th Air Force with its headquarters at March Air Force Base.