Bubonic plague had threatened San Francisco for the decades leading up to the Great Quake of 1906.  But the horrendous disaster created an even greater menace. All of the city’s sewers and water mains had been smashed. The Golden City found itself covered with stumps of open sewer pipes.  Rats suddenly had access to all parts of the metropolis. They were using the main sewers as inviting boulevards.  Even clean, well-fed white people in good houses were now faced with the same plague that had terrorized Chinatown year after year.

1906 huge quake damage downtown