From Inside Sources:

In a study released last year, R Street Institute scholars R.J. Lehmann and Daniel Semelsberger found that California is home to approximately two-thirds of Fannie Mea and Freddie Mac’s earthquake risk. These government-sponsored enterprises hold billions of dollars of mortgage debt that is supported by uninsured collateral — California homes. Specifically, the study finds that they hold more than “$355 billion in unpaid principal on mortgages in earthquake-exposed counties, representing 7.3 percent of their combined 2016 mortgage books.”