The United States Geological Survey says an earthquake with a preliminary magnitude of 3.3 struck just the San Francisco Bay area before 5 a.m. PDT Monday. The epicenter was about 24 miles east-northeast of San Francisco City Hall. The closest city to the 4:55 a.m. quake was Alamo, California, about 2 miles away. The quake had a depth of about 3.5 miles. There was no immediate word of damage or injuries. According to the USGS, the East Bay area was hit with several small earthquakes Sunday.