Operation Crossroads began with the first blast (Test Able), an air burst on 1 July; "Sakawa" was filled with cages containing various animals to be tested for radiation effects. Ground zero was above and slightly to starboard of "Sakawa"s stern. The blast set the ship afire and its force crushed her superstructure aft of her bridge, damaged her hull and she began taking on water. After the test, "Sakawa" was slightly down by the stern and had a slight list to port. The flooding progressively worsened overnight and the following morning saw her even more settled by the stern and with a greater list. The tug boat tried to beach the cruiser to prevent her from sinking, but failed as "Sakawa" started sinking by the stern almost as soon as towing began. "Achomawi" had to cut the tow cable to prevent herself from being dragged under. "Sakawa" sank at in about of water.