California Institute of Technology
It was felt as far away as Las Vegas, and the USGS says it also was felt in Mexico.
A widely felt magnitude 5.4 quake before dawn Friday was the strongest aftershock thus far.
The United States is still more than a decade behind Japan in rolling out earthquake alerts, experts say.
“We’ve heard this thunder before," one scientist said, "but this is the first time we’ve also been able to see the lightning.”
WHAT'S HAPPENING
The U.S. Geological Survey mistakenly said a magnitude 6.8 quake was on the way.
