Most of the 240 Japanese defenders on Tanambogo were aircrew and maintenance personnel from the Yokohama Air Group. Many of these were aircraft maintenance personnel and construction units not equipped for combat. One of the few Japanese soldiers captured recounts fighting armed with only hand sickles and poles. Rupertus detached one company of Marines from the 1st Battalion, 2nd Marine Regiment on Florida Island to assist in assaulting Tanambogo, in spite of advice from his staff that one company was not enough. Incorrectly believing Tanambogo to be only lightly defended, this company attempted an amphibious assault directly on Tanambogo shortly after dark on 7 August. Illuminated by fires started during a U.S. naval bombardment of the islet, the five landing craft carrying the Marines were hit by heavy fire as they approached the shore, with many of the U.S. Navy boatcrews being killed or wounded, as well as heavily damaging three of the boats. Realizing the position was untenable, the Marine company commander ordered the remaining boats to depart with the wounded marines, and he and 12 men who had already landed sprinted across the causeway to cover on Gavutu. The Japanese on Tanambogo suffered 10 killed in the day's fighting.