The Corbi family's house looks like many other modern homes in the Hollywood Hills, with white walls, large glass windows and views of downtown Los Angeles. But it has some key differences from its neighbors. The house has been built to withstand nearly every type of disaster scenario imaginable, from storms to high-magnitude earthquakes to wildfires to pandemic to a rare but potentially crippling high-frequency electromagnetic pulse attack triggered by a nuclear bomb, solar flare or specialized weapon. A wine cellar in the basement doubles as an underground bunker. If all else fails, a rooftop helipad allows for a last-ditch...