The 1987 Whittier Narrows earthquake occurred in the southern San Gabriel Valley and surrounding communities of southern California at 7:42 a.m. PDT on October 1. The moderate 5.9 magnitude blind thrust earthquake was centered several miles north of Whittier in the town of Rosemead, had a relatively shallow depth, and was felt throughout southern California and southern Nevada. A large number of homes and businesses were impacted, along with roadway disruptions, mainly in Los Angeles and Orange counties.