Second 3.9 Earthquake Rattles Nerves, Crockery in Lamorinda

Two 3.9 earthquakes, both nearly identical in motion and duration, rolled across Lamorinda and the East Bay Thursday -- courtesy of the Hayward Fault.

The first quake shook Lamorinda at 2:41 p.m. and was initially judged to be a 4.2 shaker until it was downgraded after USGS review to a 3.9 after a data review.

Moragans reported a single, sustained shock which lasted for a few seconds. The jolt triggered a rash of alarms and a few calls for help from residents whose windows shattered during the shaker. Many Lamorindans reported a single, sustained rolling jolt of about four seconds duration.

They got a repeat performance at 8:16 p.m. when a second jolt, epicentered virtually on top of the first and also logging in at 3.9, rumbled through the East Bay.

Again, there have been no reports of major damage though cautionary measures were taken as Moraga-Orinda Fire and Contra Costa County Fire stations as fire crews rolled their engines outside to prevent them from being trapped inside by a larger, more destructive aftershock.

BART trains slowed but were not ordered stopped.