The biggest earthquake I've ever experienced was the Great Eastern Japan Earthquake in 2011. I lived in Tokyo at that time and the seismic strength there was lower 5 on the Japanese seismic scale. I was working on the 15th floor of a skyscraper in Shinjuku. High-rise buildings in Japan are designed to sway in particular around the middle floors for seismic isolation. I was scared to death, and my heart was racing. The impact was so strong that I thought the epicenter must be Tokyo, but it wasn't. After the shaking stopped, we turned on the TV and learned the epicenter was Tohoku, which is far from Tokyo, and a newscaster was reiterating that there was a tsunami alert.

The first thing that came to mind was a friend of mine named Aya, who lived near the sea in Tohoku. After that massive earthquake, we Japanese are constantly on the lookout for tsunamis following earthquakes. However, at that time, we didn't understand the terror of tsunamis enough. It was also after that quake that various alerts were issued to our smartphones. With a trembling finger, I checked her Twitter timeline—all the other platforms and lines of communication had died and weren't available. Her latest tweet was: "The power has gone out. What a mess! I have to tidy up my house." She didn't know about the tsunami alert due to the blackout. Our mutual friend had just replied to this tweet: "A tsunami alert has been issued!!!! Run ASAP, Aya!!!!" I added a similar reply to it and dashed down the stairs from the 15th floor.