A rare double earthquake ravaged Venezuela on Wednesday, killing at least 920 people and leaving thousands injured. Many more are feared dead.Thousands of people have been reported missing. Some of the heaviest damage and casualties were in La Guaira, a coastal region north of the capital, Caracas.Here’s what to know about the earthquakes and the search for survivors:2 earthquakes in less than one minuteThe powerful 7.2- and 7.5-magnitude earthquakes struck 39 seconds apart along the San Sebastian fault on Venezuela’s northern coast, according to the U.S. Geological Survey.They were among the strongest in the South American nation in more than a century.The first earthquake, a 7.2-magnitude foreshock, hit west of Morón on the Caribbean coast, about 170 kilometers (105 miles) west of Caracas, with a depth of 22 kilometers (about 14 miles).The second, a 7.5-magnitude mainshock, was centered 16 kilometers (10 miles) southwest of Morón, with a depth of 10 kilometers (about 6 miles).The back-to-back earthquakes — known as a doublet because of their similarities in magnitude, time and proximity — resulted from shallow strike-slip faulting near the complex plate boundary between the Caribbean and South American tectonic plates, the U.S. Geological Survey said.