4.0 magnitude earthquake shakes Ontario area, USGS says
ONTARIO, Calif. (KABC) -- A magnitude 4.0 earthquake rattled the Ontario area Sunday morning, jolting some residents awake. Measured at a depth of about 3.54 miles, the 3:51a.m. quake was centered southeast of Ontario, according to the U.S. Geological Survey. The agency initially reported the temblor as a 4.3.