Millions of people have been ordered to evacuate in Japan due to tsunami warnings, after one of the world's strongest earthquakes struck off the coast of Russia's far east earlier. Jul 30's alerts may invoke memories of one of Japan's darkest days. Back in March 2011, a 9.0-magnitude earthquake triggered a massive tsunami that claimed nearly 20,000 lives and caused a meltdown at Fukushima nuclear plant. Since then, Japan has invested heavily in tsunami prevention and preparedness.