Actions Along The Matanikau - October Action - Action

Action

On the morning of 7 October, the two 5th Marine battalions attacked west from the Lunga perimeter towards the Matanikau. With direct-fire support from 75 mm guns mounted on halftracks, plus additional troops supplied by the 1st Raider Battalion, the Marines forced 200 soldiers from the Japanese 3rd Company, 1st Battalion, 4th Infantry into a small pocket on the east side of the Matanikau about 400 yd (370 m) from the river mouth. The Japanese 2nd Company tried to come to the aid of their comrades in the 3rd Company but were unable to cross the Matanikau and took casualties from Marine gunfire. Meanwhile, the two 7th Marine battalions and the Whaling Group reached positions east of the one-log bridge unopposed and bivouacked for the night.

Oblivious of the U.S. Marine offensive, General Nasu sent the 9th Company of the 4th Infantry Regiment's 3rd Battalion across the Matanikau on the evening of 7 October. The Japanese regiment commander received word of the U.S. Marine operation about 03:00 on 8 October and immediately ordered his 1st and 2nd battalions closer to the river to counter the Marine operation.

Rain on 8 October slowed the U.S. 7th Marines and the Whaling Group as they attempted to cross the Matanikau. Near evening the U.S. 3rd Battalion 2nd Marines reached the first ridge west of the Matanikau about 1 mi (1.6 km) from Point Cruz. Opposite their position on the east bank of the river, Company H from the U.S. 2nd Battalion 7th Marines unknowingly advanced into an exposed position between the Japanese 9th Company on the east bank and the rest of the Japanese 3rd Battalion on the west bank and was forced to withdraw. As a result, the Marines halted their attack for the night and prepared to resume it the next day. Unaware that the Marines threatened their positions on the west bank of the Matanikau, the Japanese commanders—including Maruyama and Nasu—ordered their units to hold in place.

During the night, the survivors of the Japanese 3rd Company, about 150 men, attempted to break out of their pocket and cross the sandbar at the mouth of the Matanikau. The 3rd Company soldiers overran two platoons from the 1st Raiders, who were not expecting an attack from that direction, and the resulting hand-to-hand melee left 12 Marines and 59 Japanese dead. The remaining 3rd Company survivors were able to cross the river and reach friendly lines. According to Frank J. Guidone, a Marine participant in the engagement, "The fight was hours of hell. There was yelling, screams of the wounded and dying; rifle firing and machine guns with tracers piercing the night–(a) combination of fog, smoke, and the natural darkness. Truly an arena of death."

On the morning of 9 October, the U.S. Marines renewed their offensive west of the Matanikau. The Whaling Group and the 2nd Battalion 7th Marines—commanded by Lieutenant Colonel Herman H. Hanneken—reached the shoreline around Point Cruz and trapped large numbers of Japanese troops between themselves and the Matanikau River, where the Japanese took heavy losses from U.S. artillery and aircraft bombardment. Further west, Puller's 1st Battalion, 7th Marines trapped the Japanese 2nd Battalion, 4th Infantry in a wooded ravine. After calling for massed artillery fire into the ravine, Puller added the fire of his battalion's mortars to create, in Puller's words, a "machine for extermination". The trapped Japanese troops attempted several times to escape by climbing the opposite side of the ravine, only to be cut down in large numbers by massed Marine rifle and machine gun fire. Having received intelligence information that the Japanese were planning a large surprise offensive somewhere on Guadalcanal, Vandegrift ordered all the Marine units west of the Matanikau to disengage and return to the east side of the river, which was accomplished by the evening of 9 October.