Transcript for Southern California shaken by another earthquake overnight
Now to that huge earthquake in California rocking homes and businesses as you can see. An incredible 4,800 aftershocks reported. Many more expected. Firefighters trying to battle blazes like this that have been breaking out. That new quake stronger than Thursday's 6.4. Already the worst in 20 years. Here's ABC's Marcus Moore. Get under the table! Get under the table! Reporter: The force of that powerful 7.1 earthquake shaking southern California. . Oh, my god! Reporter: The second major quake in less than 48 hours igniting homes. Structure fires as well as several outside fires and hazardous conditions. Reporter: This grocery store right near the epicenter losing power as customers and employees step over broken glass to escape. The air is really thick. Reporter: One employee helping a startled woman out of the store. Aisle by aisle the floor disappearing under fallen merchandise. Brayden, get over here! Brayden! Reporter: This woman rushing to grab her 2-year-old son as the trailer just feet away swayed back and forth. There's a rock slide down here at the canyon. Reporter: Nearby rock slides shutting off this highway. Scientists surveying the damage right next to the fault line. We met this family looking at the damage in their own homes. You could hear things? We could hear things. You could hear things breaking. You could hear all that. You could hear it being thrashed. Reporter: The epicenter of Friday's quake, 11 miles from Thursday's 6.4 tremor that was already California's strongest quake in 20 years. And officials believe it was only the precursor to the massive 7.1. The quake felt throughout southern California and in two other states. So powerful it forced some to sleep outside. Feels safer out here. At least if the house collapsed we wouldn't be inside. Reporter: Tonight more than 4,800 after shocks rattling nerves. California's governor requesting a presidential emergency declaration for the communities impacted as this entire region remains on edge. Marcus Moore joins us live. Marcus, we saw that family sleeping outside fearful of more tremors. What are people in the impacted communities telling you about the potential for more powerful quakes? Tom, they're going to begin to recover. Some people are starting over from scratch. Like the family that lived in this house, you see nothing left on the inside. It burned down in the aftermath of Friday's earthquake. When you look at the wider region, Tom, there's a sense this area has been spared. When you consider America's second largest city Los Angeles is not far from here and these two powerful earthquakes hit in less densely populated areas. Marcus, thank you. Let's bring in seismologist Lucy Jones. You earlier warned of a potential of a stronger quake. That happened. What are the risks of another quake at this point or anything hitting any time soon? They're small. They're not zero. At this point we're down to a few percent chance that we could have another very large earthquake, 7 or above. Most likely we've seen the largest one. That means plenty of magnitude 5 and 6s that would be part of the after shock sequence. Should folks that live in southern California be on alert? The only people that should be on alert are the ones that live near the earthquake. If you live in the southern Owens valley, yes, expect to feel lots of earthquakes with the potential of damaging winds. For those of us that live in the downtown Los Angeles this doesn't change the risk of earthquakes in the metropolitan area, either to increase it or decrease. Dr. Jones, thank you. Now to the severe weather
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