There have been many rumors about the various things that went on at Los Alamos over the centuries. Secret underground tunnels going thousands of miles. Alien research. Yes, those rumors were not just at the Area 50 pluses. Entrances to secret underground cities for the ultra rich to shelter in during an apocalypse. Those and a legion more have been floated about Los Alamos, though very few have been proven. There is at least some truth to the rumors that underground tunnels linked Los Alamos with numerous nearby military bases and research institutions, though. The exact location and destinations of the tunnels are still beyond top secret, but we know some were heavily used during the Second Great Depression to keep Los Alamos connected with her far-flung research network throughout the American Southwest. The tunnels helped keep the entire network operational during the worst of the chaos. They also enabled Kitty to spread her code via physical lines, without the vagaries of wireless communications, giving her a massive reach in those early days of AI sapience.