Short answers, pulled from the story.
The 2011 Tōhoku earthquake and tsunami occurred on the 11th of March 2011 at 14:46 JST. This megathrust earthquake measured 9.1 on the moment magnitude scale and lasted for approximately six minutes.
In Miyako, Iwate Prefecture, the tsunami waves surged to heights of 38.9 meters during the 2011 Tōhoku earthquake and tsunami. This record run-up height exceeded the 1896 Sanriku earthquake and swept away entire towns.
The tsunami waves overtopped the seawalls and destroyed the diesel backup power systems at the Fukushima Daiichi Nuclear Power Plant during the 2011 Tōhoku earthquake and tsunami. This led to severe problems including three large explosions and radioactive leakage from the meltdowns of three reactors.
Official figures released in 2021 reported 19,759 deaths and 2,553 missing in the 2011 Tōhoku earthquake and tsunami. The leading causes of death were drowning, burning, and being crushed by heavy objects.
Snow fell across several areas where the 2011 Tōhoku earthquake and tsunami struck, further worsening conditions and hampering rescue efforts. The 18th of March was the coldest of that month, recording minus 15 degrees Celsius in Sendai.