By the time the students at Garden Gate Elementary School in Cupertino began their earthquake drill Friday morning, the shockwaves from the earlier earthquakes had long passed. But at Memorial Stadium in Berkeley, things were different.
"The first thing I said to a friend was, 'Is there an earthquake or did someone drop something on the roof?'" said one stadium worker.
People felt the first quake -- a magnitude-4.0 -- as far away as San Francisco. The second, an aftershock that registered as a 3.8, hit six hours later.
The irony is that both quakes happened on a day when California practiced a statewide drill for earthquake preparedness. The second earthquake felt more severe because it was shallower -- three miles down instead of six.
"I have been here 20 years and just felt two," one resident said. "I'm nervous."
Mindfulness would be a better option, according to the U.S. Geological Survey, which says the earthquakes were not a quakestorm nor were they a build-up to something bigger.
The second earthquake took place on a known branch of the Hayward fault.
"This is in a zone where we have had dozens of earthquakes over the last several decades," said Walter Mooney with the USGS. "It's a known, active area. We can't say that it's unusual in this location."