Eighth Army had in reserve three understrength infantry regiments and the 2 @-@ battalion British 27th Infantry Brigade which was not yet completely equipped and ready to be placed in line : The 1st Provisional Marine Brigade at Changwon , 6 miles ( 9 @.@ 7 km ) northeast of Masan , preparing for movement to the port of Pusan ; the US 27th Infantry Regiment of the 25th Division which had arrived at Masan only the night before at 20 : 30 to relieve the 5th Regimental Combat Team , which was then to join the 24th Division in the Taegu area ; and the US 19th Infantry Regiment of the US 24th Infantry Division , then with that division 's headquarters at Kyongsan southeast of Taegu . Walker alerted both the 24th Division headquarters , together with its 19th Regiment , and the 1st Provisional Marine Brigade to move at a moment 's notice ; the 24th Division either to the 2nd or 25th Division fronts , and the marines to an unannounced destination .