In Mexico, the country’s strongest earthquake in a century struck off the west coast early Friday, leveling buildings in the impoverished states of Chiapas and Oaxaca and triggering tsunami warnings across the Pacific. The 8.1-magnitude quake struck at a shallow depth of just 43 miles, making it particularly dangerous. There were early reports of at least 15 deaths, but that toll is expected to rise dramatically after the U.S. Geological Survey warned of high casualties and said the disaster is likely widespread. The quake triggered Pacific Ocean tsunami sensors, but Mexican President Enrique Peña Nieto later said the waves were not as high as feared and major damage from tsunamis is unlikely. The quake was so powerful it rattled buildings, broke windows and knocked out power in parts of Mexico City, more than 450 miles away.