In the early evening of 21 July 1942, Japanese troops landed close to Gona. The Japanese advance party moved rapidly towards Kokoda, reaching the Kumusi, at Wairopi in the afternoon of 23 July. The PIB and Australians engaged the advancing Japanese with ambushes. B Company, 39th Battalion assembled a force (including what remained of the PIB) to make a stand near Oivi on 26 July. One platoon remained at Kokoda. Threatened with encirclement, the force at Oivi withdrew south to Deniki. Having lost contact, the platoon at Kokoda also withdrew to Deniki on 27 July. With the force reassembled, it reoccupied the village unopposed on 28 July. The first battle at Kokoda was fought over 28–29 July. Repeated, determined attacks caused the Australians to withdraw to Deniki. Owen, commanding officer of the 39th Battalion, was mortally wounded in the fighting.