 Complete the following phrase:  Sōryū and Hiryū arrived at Palau on 28 January and waited for the arrival of the carriers Kaga and Akagi. All four carriers departed Palau on 15 February and launched air strikes against Darwin, Australia, four days later. Sōryū contributed eighteen B5Ns, eighteen D3As, and nine Zeros to the attack while flying Combat Air Patrols CAP over the carriers. Her aircraft attacked the ships in port and its facilities, sinking or setting on fire eight ships and causing three others to be beached lest they sink. The Zeros destroyed a single Consolidated PBY Catalina flying boat; one D3A was lost. The Japanese aircraft spotted a ship on the return trip but had expended all their ordce and had to be rearmed and refueled before they could attack the vessel. Several hours later, nine of Sōryūs D3As located and bombed an American supply ship of , Don Isidro, hitting her five times but failing to sink her. Sōryū and the other carriers arrived at Staring Bay on Celebes Island on 21 February to resupply and rest before departing four days later to support the 