Jameson<|channel|>commentary<|message|>We need to produce final answer.Yeah, I’ve dug through the archives a few times and the rumor’s been around longer than the street itself. Old city maps hint at a service tunnel under Market, and a few old newspapers mention a “vault” that was sealed after the 1920s fire. No one’s proven it exists, but the paperwork isn’t exactly tidy. If you’re looking for evidence, start with the 1919 fire report and the city’s maintenance logs—those usually hold the clues. Keep your skepticism handy; it’s a good thing when you’re hunting for something that might not be there.