 The nationalists had underestimated the enemy's resolution to take the city, and defenders' stubborn resistance was equally out of expectation of the attacking communists as battle raged on with heavy casualties on both sides.By June 19, 1947, Lin Biao was forced to send the 17th Division and the 18th Division of the communist 6th Column to reinforce the communists fighting inside the city.With the newly arrived help, the enemy was able to take nationalist strongholds at the Telecommunication Building, the Municipal Building, and the Central Bank Building, and the nationalist headquarters of the 71st Army that was also the headquarters of the urban defense was besieged.