The San Andreas star explains her penchant for pajamas – it all started with an earthquake ...

By Scott Huver
Updated May 29, 2015 03:45 PM
Rob Latour/Invision/AP

Carla Gugino hasn’t slept in the nude for more than two decades – and she has a very good reason. It’s called earthquake preparedness.

The actress, who currently stars opposite longtime pal Dwayne "The Rock" Johnson in the earthquake epic San Andreas, says she’s terrified of nocturnal natural disasters.

“I was in the Northridge quake in 1994, living in the Pacific Palisades with my boyfriend at the time,” she tells PEOPLE of the massive, magnitude-6.7 earthquake that caused serious damage around Los Angeles (and was felt as far away as Las Vegas). “I woke up from a dead sleep. And I was sleeping naked, just in my birthday suit.”

“I got up and I could not find any clothes – and the ground was shaking, things were falling,” says Gugino. “I was just going to run out of that house, just naked as the day I was born. But I finally found my robe on the ground. I put that robe on, and I have not, to this date, slept naked in California ever again!”

Lesson learned.