: AP has reported, citing Japan Meteorological Agency, that the magnitude 6.9 earthquake off the Fukushima Prefecture coast Tuesday was an aftershock of the magnitude 9.1 earthquake that occurred in 2011 and triggered a deadly tsunami with waves up to 133 feet. The agency warned that in the next few days, another large quake could hit, urging residents to remain cautious for about a week, according to AP. The magnitude 6.9 earthquake Tuesday was the strongest since the 2011 quake.