[Cooper:] A magnitude 5.1 earthquake struck Southern Californians with no warning over the weekend. Here's what it looked like at an ice cream parlor near Los Angeles. Dozens of aftershocks followed. It struck on a fault that's less well known than the San Andreas, but potentially even more dangerous. Jason Carroll investigates.
[Jason Carroll, Cnn Correspondent:] Friday night's performance of "Bye-Bye Birdie" interrupted when the earth started to shake.
[Unidentified Male:] Ladies and Gentlemen, please stay seated.
[Carroll:] Surveillance cameras rolling, with a magnitude 5.1 quake sent a convenience store owner jumping the counter for cover.
[San Deep Rem, Owner, Food Circle:] My first reaction was I'm going to run. I saw them run, I said, let's go.
[Carroll:] The owner and others ran outside. A small part of the store's roof was damaged. Food knocked into the aisles.
[Rem:] The floor starts shaking, something's wrong you have to go.
[Carroll:] Customers at an ice cream parlor, the home of the eight scoop earthquake sundae got a taste of the real thing. At an apartment near the epicenter, fallen pictures, frayed nerves.
[Unidentified Female:] I ran into the middle of the street into the arms of this stranger, and we were in the middle of the street just like hugging.
[Carroll:] More than 100 aftershocks hit the region including a magnitude 4.1 that struck Saturday afternoon. The quake centered around 25 miles south of downtown Los Angeles on the Puente Hills fault. One seismologist have been closely watching.
[Dr. Lucy Jones, Seismologist, U.s. Geological Survey:] When we have a big earthquake on the Puente Hills, the strong shaking is going to be downtown Los Angeles, Hollywood, east L.A. and we are going to see a much, much higher level of damage.
[Carroll:] While there were no injuries reported and damage mostly minor, tremors were a wakeup call, what it means to live in a quake country. They haven't seen a major one since the 1994 North Ridge quake. The magnitude 6.7 was felt as far away as Las Vegas, 57 were killed, 5,000 injured. Property damage estimated at $20 billion. [on camera]: What was learned after that happened?
[Anthony Akins, Los Angeles Fire Department:] We saw In North Ridge we need to have those channels of communication open. We need to be able to respond quickly, not just within ourselves, but with L.A. City and some of the nearby agencies, one of the big focuses that came out of North Ridge.
[Carroll:] The L.A. County Office of Emergency Management estimates there is an 86 percent chance of a magnitude 7.0 or greater earthquake hitting California in the next 30 years. Akins says the recent quakes are a reminder to be prepared. While the tremors sent some ducking for cover. His message not being felt by everyone.
[Jb Carlin, Los Angeles Resident:] Nervous and not prepared.
[Khara Aerts, Los Angeles Resident:] I'd say we're sufficiently, sort of ready, as ready as one could be.
[Cooper:] Jason, you talk about that 86 percent chance of a 7.0 or greater earthquake hitting California in the next 30 years. There's no way to predict when or where that can happen?
[Carroll:] Right. I mean, it could happen on the San Andreas fault and the Puente Hills fault. That was a fault that was recently discovered. I believe in 1999, and you look at what happened at North Ridge in 1994, that fault scientists didn't know about until unfortunately after their earthquake had happened. So the point really is, when you talk to emergency officials, it's going to happen, where it's going to happen, they're not sure, but it is going to happen, be prepared. This weekend should be a reminder to do some basic things, having supplies such as food and water for at least 72 hours, have those supplies ready this weekend a reminder as to the reason why -Anderson.
[Cooper:] Medication as well. Jason Carroll, thanks very much. Up next, a new GM recall affecting more than a million vehicles and the governor of Washington State making a special request to President Obama to assist the victims in the devastating landslide. More on that ahead.