A preliminary 3.7 magnitude earthquake struck near Concord on Sunday morning, according to the United States Geological Survey.  The quake, which struck at 8:49 a.m., was centered 0.7 miles east-southeast of Concord.  Further information was not immediately available. This is a developing story. Details may change as more information becomes available. Stay tuned for updates. BAY AREA QUAKE CENTRAL You can take steps to plan and prepare for the next big one. Access our Bay Area Quake Tracker, the latest earthquake stories, extensive quake prep checklists, videos and many other disaster preparedness resources all in one place: NBCBAYAREA.COM/QUAKES