Sharply vigilant during hostile air raids against Allied ships on radar picket duty off Okinawa on 10 June, Lt. McCool aided materially in evacuating all survivors from a sinking destroyer which had sustained mortal damage under the devastating attacks.

When his own craft was attacked simultaneously by 2 of the enemy's suicide squadron early in the evening of 11 June, he instantly hurled the full power of his gun batteries against the plunging aircraft, shooting down the first and damaging the second before it crashed his station in the conning tower and engulfed the immediate area in a mass of flames. Although suffering from shrapnel wounds and painful burns, he rallied his concussion-shocked crew and initiated vigorous firefighting measures and then proceeded to the rescue of several trapped in a blazing compartment, subsequently carrying 1 man to safety despite the excruciating pain of additional severe burns. Unmindful of all personal danger, he continued his efforts without respite until aid arrived from other ships and he was evacuated. By his staunch leadership, capable direction, and indomitable determination throughout the crisis, Lt. McCool saved the lives of many who otherwise might have perished and contributed materially to the saving of his ship for further combat service. His valiant spirit of self-sacrifice in the face of extreme peril sustains and enhances the highest traditions of the U.S. Naval Service.