The temblor struck about 8:17 p.m. at a depth of 6.1 miles. Its epicenter was 2 miles north of Yorba Linda, and it was felt as far away as 70 miles to the south parts of San Diego County and 40 miles to the east in Redlands.
The Orange County Fire Authority went into earthquake mode, checking to make sure all its equipment was functioning properly and facilities for damages.
"The things that we're checking are high-end areas like school, bridges, underpasses," said Capt. Pat Howard of the OCFA, adding water and gas plants to that list.