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When Jacob Margolis felt the biggest earthquake to rumble across Southern California in decades, he didn’t panic. He didn’t jump up to check on his 18-month-old in another room.

“We need to sit here,” Mr. Margolis thought. “Everything is going to be totally fine.”

[Read more about Friday night’s 7.1-magnitude temblor.]

If you’re now thinking that this guy knows something you don’t, you’re probably right.

Mr. Margolis, a journalist with KPCC, spent months researching what to do when a major quake hits for the podcast he hosts, aptly titled, “The Big One.” (You can listen to all the episodes here. Each one also includes a helpful resource guide.)

Over the weekend, I asked Mr. Margolis for some advice. Here’s what he said:

Do not run to the nearest doorway when you feel shaking.

Mr. Margolis said the idea that doorways are the safest parts of buildings is a persistent myth that seems to be traceable back to the 1800s, when the doorway of an adobe house was the only thing left standing after a big quake.