Japan observed a moment of silence Saturday as it marked the sixth anniversary of a killer tsunami triggered by the massive March 11, 2011, earthquake that left more than 20,000 dead or unaccounted for and 120,000 still displaced.

A solemn atmosphere took hold of the hardest-hit northeastern prefectures of Iwate, Miyagi and Fukushima at 2:46 p.m., as the nation offered silent prayers to those who perished in the biggest natural calamity in Japan's postwar history, a disaster that devastated large swaths of the Tohoku region.

The death toll from the magnitude-9 quake and ensuing tsunami — plus numerous aftershocks in the months following — had reached 15,893 as of Friday, according to National Police Agency statistics.