Another option, along the Applied Math alternatives, is a an Operations Research MS. It's a wide field of mostly applied math, statistics and optimization. You can pick your concentration and most programs have a strong link to an industry funded projects, but your work does not need to be funded research. You can essentially make anything you want out of it, and at the same time be exposed to many fields.

Also, the US government has many "Operations Research Analyst" named openings in defense, DOE and intelligence, as well as many defense contractors. This could be your "safety field".