Volcano eruption triggers tsunami alerts from Japan to U.S.
A tsunami has thrashed Tonga after an undersea volcano erupted off the coast of the island nation. Warnings have been issued from Japan to the United States. The Japan Meteorological Agency said potentially three-meter-high waves have reached the country's Pacific coast. Tsunami waves have already triggered minor flooding in the U.S. state of Hawaii. Tonga is reeling in the aftermath.