LOS ANGELES -- A powerful 7.1 earthquake shook Southern California, cracking buildings, breaking roads and causing power outages on Friday, just one day after a magnitude 6.4 hit the same general area -- while seismologists warned that large aftershocks were expected to continue for days, if not weeks.
The quake, centered 11 miles from Ridgecrest area, struck at 8:19 p.m. and was originally listed as a 7.1, was downgraded shortly after and then upgraded back to a 7.1. Friday's earthquake was about 10 seconds longer than the quake on the Fourth of July in Searles Valley.
Friday's temblor is the largest Southern California quake in at least 20 years and was followed by a series of large and small aftershocks, including a handful above magnitude 5.0.
Seismologists said on Saturday that they had measured at least 2,600 aftershocks of magnitude 3.0 and greater. And by the time they finish analyzing all the data, they'll expect to catalog 30,000 of 1.0 magnitude or greater.
Caltech seismologist Egill Hauksson said the likelihood of another earthquake in the area of 7.0 or greater is now 3%, down from the 6% probability estimated on Friday.
But he said the chance of another quake of 6.0 or greater is 27%.
"So we're likely to see maybe one or two of those in the next week," Hauksson said Saturday morning.
The area in and around Ridgecrest, already trying to recover from the previous temblor, took the brunt of damage. Kern County fire officials reported "multiple injuries and multiple fires" without providing details. San Bernardino County firefighters reported cracked buildings and a minor injury.
"We know of no fatalities. There have been a lot of ambulance calls for help," Kern County Fire Chief David Witt said at a news conference. "We're launching a lot of people ... I am very confident that we can take care of the situation."
Seismologist Dr. Lucy Jones said the 6.4 is now a foreshock, and another 6.0 quake "would not be surprising." The new, larger quake was on the same fault and part of the same sequence.
There is about a 1-in-10 chance that another 7.0 quake could hit within the next week. There is a 9 in 10 chance that the 7.1 will be the largest in Searles Valley. Jones said aftershocks from the new main quake could occur for three years.
"Like any quake, today's M7.1 has a 1 in 20 of being followed by something even bigger. Smaller quakes - M5s are likely and a M6 is quite possible," Jones said in a tweet.
VIDEO: Man records terrifying moment 7.1 magnitude earthquake hits Ridgecrest
Gov. Gavin Newsom activated the state Office of Emergency Services operations center "to its highest level." Soon after, a state of emergency was declared for San Bernardino County. The governor requested that President Donald Trump issue an emergency declaration so the state could receive federal aid.
"The state is coordinating mutual aid to local first responders," he said.
Ridgecrest earthquake: Reports of fires, calls for ambulances in Kern County
People reported feeling the earthquake in areas as far as San Francisco and Las Vegas. The quake was felt downtown as a rolling motion that seemed to last at least a half-minute.
The U.S. Geological Survey said it also was felt in Mexico.
VIDEO: Dr. Lucy Jones gives 26-second early warning on aftershock that hit live on air
Disneyland in Orange County and Six Flags Magic Mountain in Santa Clarita closed their rides.
An NBA Summer League game in Las Vegas was stopped after the quake. Speakers over the court at the Thomas & Mack Center continued swaying more than 10 minutes after the quake.
Dramatic video showed Dodger Stadium shaking during the temblor during the home team's game against the San Diego Padres. But the game went on, and the Padres won, 3-2.
"Not many people can say they threw a strike during an earthquake," Eric Lauer, who was on the mound at the time, said later. "My ball, my pitch, started an earthquake."
RELATED: Earthquake rattles Dodger Stadium during game
Power outages have been reported in Kern, Inyo and San Bernardino counties, according to Southern California Edison. About 13,000 people have no electricity in the Ridgecrest area.
Nearly 900 residents in the town of Fillmore are also without power.
The Department of Water and Power says power is out in areas such as Encino and Valley Glen. It is affecting about 1,000 customers.
Crews caution everyone that if they see a downed power line to assume it is charged and to stay away.
EMERGENCY PHONE NUMBERS:
The city of Ridgecrest wants to make sure local residents affected by the earthquake are aware of these resources and phone numbers:
Reporting building damage to residential structure: (760)499-5083.
SoCal Edison: (800)655-4555
Non-emergency police or missing persons reports/inquiries: (760)499-5100
Red Cross cooling and evacuation center: 100 W. California Ave., Ridgecrest
An image from the California Highway Patrol in Bakersfield shows large rocks on State Route 178 through the Kern River Canyon, which has been shut down.
The Associated Press contributed to this report.