A powerful magnitude 7.8 earthquake struck off New Zealand's Kermadec Islands, triggering a tsunami in the region, the U.S. Geological Survey and the U.S. Pacific Tsunami Center said on Wednesday. The quake, initially reported as a magnitude 7.9, triggered a tsunami warning for New Zealand, the Kermadec Islands and Tonga, the U.S. Pacific Tsunami Center said. "Sea level readings confirm that a tsunami was generated. This tsunami may have been destructive along coastlines of the region near the earthquake epicenter," the U.S. Pacific Tsunami Center said in its warning. It struck at 7:03 a.m. on Thursday (1903 GMT on Wednesday)...