When I saw the first trailer for the movie San Andreas, I knew it wasn’t going to be realistic. And that really bugged me. There are real earthquake risks in California. What I didn’t realize was how scary those risks are and how unprepared the state still is for them. The real “Big One” will provide plenty of death and destruction, and it may last for years. What can we expect? Read my story for Smithsonian.com: What Will Really Happen When San Andreas Unleashed the Big One?