Aftershocks awaken jittery Bay Area residents

The USGS said a 3.9 magnitude aftershock struck near American Canyon at 5.33 a.m. It was the largest since the 6.0 quake hit in the same area, injuring dozens of people and causing extensive damage in nearby Napa and other Wine Country communities.

A second followed quickly, measuring 2.7 struck at 5:38 a.m.

There were no reports of any additional damage.