This week Muni offered a rare glimpse into their archives by releasing never-before-seen photos from the 1906 earthquake.
It's unclear why Muni wouldn't share the photos until now, but they paint a vivid portrait of a city in ruins. The photographer was John Henry Mentz, an employee of one of the many rail operators that preceded today's transit system.
One particularly vivid photos shows refugees in Alamo Square, just feet from the "Full House" houses, watching a city engulfed in fire and smoke.
Coincidentally, contemporary data shows that some things haven't changed since the photos were taken. Muni reports show that the average speed today is the same as it was 100 years ago.
Historians have been bowled over by the photos of the devastation, and hope that Muni's newfound spirit of openness will continue. There's no telling what other historical resources they may have locked away.
Meanwhile, Muni spent most of today tied in knots as mechanical issues shut down the subway system. Some riders reported being trapped in trains near Embarcadero for an hour.