Members of Task Force Manchu who escaped from Hill 209 brought back considerable intelligence information of North Korean activity in the vicinity of the Paekchin ferry crossing site . At the ferry site the North Koreans had put in an underwater bridge . A short distance downstream , each night they placed a pontoon bridge across the river and took it up before dawn the next morning . Carrying parties of 50 civilians guarded by four North Korean soldiers crossed the river continuously at night , an estimated total of 800 @-@ 1 @,@ 000 carriers being used at this crossing site .