Article Photos: Oklahoma's seismic activity may not be over, experts say 8/40

Chad Devereaux works to clear up bricks that fell from three sides of his in-laws' home in Sparks, Okla., Sunday, Nov. 6, 2011, after two earthquakes hit the area in less than 24 hours. The weekend earthquakes were among the strongest yet in a state that has seen a dramatic, unexplained increase in seismic activity. (AP Photo/Sue Ogrocki) ORG XMIT: OKSO115