(security windows, earthquake straps, etc...)

One of the questions I've been trying to decide is if it's worth spending the money for Earthquake insurance.

The fact that you state in your lease that 14 people can live there could open you to liability in the event of a fire, earthquake or some other disaster.

@Suzanne Griffiths  same with many inner city areas I can show you amazing wood work in San Francisco post 1907 earthquake and homes framed in solid redwood ( which is over the top expensive today)I was in Milwaukee last summer and my mom was showing me were she grew up in the late 30's and 40's homes were spectacular they would be 700 to 2 million on the west coast..

Sounds like an explosion/earthquake from hell LOL! 

Anyone working here legally will have a social security number, though - even professional athletes (I once rented to a soccer player for the Earthquakes from Sierra Leon). 

When the next big earthquake comes, prices will collapse.

I wouldn't shy away from it just because it is in a floodplain, but I would definitely do my research to determine the risk I am taking and what it would take to mitigate that risk.The same could be said for properties at risk from tornados, hurricanes, tsunamis, earthquakes, landslides, and wildfires. 

You forgot the tornados and earthquakes!

Earthquake insurance is separate and prohibitively expensive and almost no one has it.