A preliminary 3.5-magnitude earthquake shook the Upland area Monday, according to the U.S. Geological Survey.
The temblor, which hit about four miles northwest of the Rancho Cucamonga area at 7:28 p.m., had recorded more than 330 responses on the USGS website from residents who said they felt it.
"I felt it too..Felt like a truck hit the side of our building," Alejandra Cervantes said on NBC4's Facebook page.
Residents from Pasadena, Montclair, Ontario and beyond said they felt shaking.
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"It was quite a rumble in northwest Ontario. Cats now hiding under the bed," S Kay Murphy said on NBC4's Facebook page.
There were no immediate reports of damage.