4.0 earthquake shakes San Francisco

SAN FRANCISCO — A 4.0 earthquake just north of San Francisco briefly closed the BART tunnel under San Francisco Bay as workers inspected the tracks.

There were no immediate reports of damage.

The earthquake struck in Piedmont, a suburb next to Oakland, at 6:49 a.m. local time.

The U.S. Geological Survey originally reported it as a magnitude 4.2 temblor but quickly adjusted it to 4.0.

The BART subway system paused operations briefly while workers inspected the tracks in the tunnel that goes under the bay. The inspection is standard procedure after an earthquake. Trains were quickly running again.