Had a few free minutes while visiting NAVSTA Pearl Harbor, HI one time with a friend. While walking down one end of the old HQ building we saw a door set into one of the pillars holding up the 2nd story porch on that end of the building. Curiosity got the best of us and we entered this door to see a steep and narrow stairwell which we went down. At the bottom was a very small vestibule with a plexiglas window in its upper half, and a three or four-inch slot in the bottom of the glass to push envelopes and papers through, apparently. Obviously a guarded door with a sentry post on the inside, now unmanned; classified messages and other materials must have been handed back and forth through the slot, and no doubt many an ID card was reviewed at this station. The plexiglas was no longer covered and we could see into the room, which was dimly lit. I tried the knob and it gave right away. As soon as we walked into this room, we both knew what it was. It was the room occupied by the decrypters that made possible the US victory at Midway. Although all furnishings had been removed from the room there were cutout spaces in the floor tile showing where teletype machines and other devices had been located. Desk sites were also plainly visible. The room was rather shabby (a pity) and obviously had not been occupied for a long time. Lots of dust. I leave it to your imaginations what it felt like to walk through this room and reflect on what had happened here, and how the fates of two nations turned on what was accomplished there.
A book on the subject, published long after this visit, shows me there is now a plaque emplaced on one side of the pillar to denote the room at the bottom of the stairwell was at one time home to FRUPAC (Fleet Radio Unit Pacific), which contributed mightily to America's winning of WWII in the Pacific.