There has been an explosion at the Fukushima No 1 nuclear plant (green balloon on the map) no 3 reactor, around 11:01 local time. It is believed that this was a hydrogen explosion, like the explosion that took place at the no 1 reactor. The electricity company (TEPCO: Tokyo Electric Power Company) and the Nuclear and Industrial Safety Agency have not detected massive radiation leaks after this incident, and the containment vessel remains intact.
The number of people in shelters is now estimated to be over a half a million (530,000), and the death tolls are rising. Around 1,000 bodies have been discovered in Minami-Sanriku (purple balloon on the map), and over 1,000 bodies have been washed up on the beaches of Oshika Peninsula (blue balloon on the map).
Tokyo and the surrounding region had been in a grip of transport chaos in the morning rush hour, because of the announced rolling blackouts. Trains are running very infrequently, if at all. People are asked not to travel unless it is necessary or urgent. If there is a need to travel, it is strongly advised to consult the relevant websites of the train companies.
This is going to be another difficult, tortuous, fearful, grave day.
A note on the sources
I have relied on information available at Japanese internet sites, mainly asahi.com and Yomiuri Online, the two largest daily newspapers in the country, and Kahoku Online Network, a regional paper, as well as official sources, such as Japan Meteorological Agency and the National Police Agency.