_Three Hills Designated 105--RCT-7 North of the Han--Attack Continued by RCT-5--Modified Plan of Corps Attack--Climax of the Marine Assault--The Epic of Dog Company--River Crossing of RCT-1_ During the night of 21–22 September an NKPA shell crashed through the roof of the native house serving as CP of the 5th Marines northwest of Seoul. The explosion wounded Lieutenant Colonel Hays so severely that the regimental executive officer required immediate evacuation. Lieutenant Colonel Murray, who escaped with a slight cut, directed that the CP be moved to a cave on the reverse slope of a hill. Thus did the enemy serve notice that henceforward the battle for the northwest approaches to Seoul would be furiously contested. Yongdungpo had been taken by the 1st Marines only after a grim, three-day struggle in which the Korean Reds made their first real stand as distinguished from delaying operations. And now it was the turn of the 5th Marines to meet opposition such as that regiment had not encountered since D-day. Two new NKPA units had much to do with the sudden stiffening of resistance. One was the 78th Independent Regiment, commanded by Colonel Pak Han Lin. This unit, numbering about 2,000 recruits in July, was organized into three battalions of infantry supported by medical, motorcycle, weapons, reconnaissance, mortar and 76mm gun companies, and an engineer platoon. Another recent arrival which won the respect of the Marines for rugged fighting qualities was the 25th Brigade of 4,000 to 5,000 troops. Commanded by Major General Wol Ki Chan, who had reportedly studied in Russia in 1947, the unit was made up of four heavy weapons battalions and an infantry battalion in addition to engineer, 120mm mortar, heavy artillery, and brigade artillery battalions.[360] [360] 1st MarDiv _SAR_, Annex Baker, and Queen Queen:Baker, app. I. It was literally a fight to the death for these two NKPA outfits, which were all but wiped out of existence by the Marines of RCT-5 during the battle for Seoul. But while they lasted, the 78th Regiment and 25th Brigade put up a determined and at times desperate resistance in hill country well adapted to defense. _Three Hills Designated 105_ The grapple for the northwest approaches to Seoul began in deadly earnest at 0700 on the morning of 22 September. From north to south, the three assault battalions of the reinforced 5th Marines were the 3d on the left, the 1st KMC in the center, and the 1st on the right. They were jumping off from the high ground about three miles southeast of Haengju along a line bounded by Hill 216 on the north, 104 in the center, and 68 on the south.