 All 500 men of the 3rd Battalion were lost just before the war started when their transport was sunk while attacking Pusan harbor by the Republic of Korea Navy.For the remainder of its existence the regiment was whittled down by losses until it numbered no more than 1,500 men and could not muster more than three battalions.During the planning for the invasion of South Korea in the years before the war, the North Korean leadership began to create large numbers of commando and special forces units to send south.