While on patrol in the channel between Florida Island and Savo Island, in the early hours of 9 August, Quincy was attacked by a large Japanese naval force during the Battle of Savo Island.
"When I reached the bridge level, I found it a shambles of dead bodies with only three or four people still standing. In the Pilot House itself the only person standing was the signalman at the wheel who was vainly endeavoring to check the ship's swing to starboard to bring her to port. On questioning him I found out that the Captain, who at that time was laying near the wheel, had instructed him to beach the ship and he was trying to head for Savo Island, distant some four miles (6 km) on the port quarter. I stepped to the port side of the Pilot House, and looked out to find the island and noted that the ship was heeling rapidly to port, sinking by the bow. At that instant the Captain straightened up and fell back, apparently dead, without having uttered any sound other than a moan."
Quincy sustained many direct hits which left 370 men dead
and 167 wounded. She sank, bow first, at 02:38, being the first ship
sunk in the area which was later known as Iron bottom Sound.
Quincy's wreck was discovered and explored by Robert Ballard and his crew in July and August of 1992. Quincy sits upright in roughly 2,000 feet of water. Her bow is missing forward of her number 1 turret, both forward turrets are trained to starboard, with turret 1 featuring a jammed gun, and one of turret 2's guns burst. Of the superstructure, the bridge is heavily damaged but intact, both funnels are missing, and the float plane hangar completely collapsed. Quincy's stern is bent upwards aft of the number 3 turret, and heavily damaged by implosions.