Day 5 – Tuesday, March 15
- An explosion hits Fukushima Daiichi's No. 2 reactor in the morning. Readings indicate some damage to the No. 2 reactor's suppression pool, a donut-shaped reservoir at the base of the reactor's containment vessel.
- A fire is ignited in the No. 4 reactor building Tuesday, but is later put out, according to officials.
- The plant is emitting as much radiation in one hour as it normally would in six months, but government spokesman Yukio Edano says: "The possibility that a large amount of radiation has been released is low."
- The head of France's Nuclear Safety Authority, upgrades the international alert from a level 4 disaster to a level 6 incident.
- Foreign companies begin to order evacuations of their employees.
Day 6 - Wednesday, March 16
- A fire breaks out at the building housing the No. 4 reactor. It's believed to be the same spot where a fire broke out Tuesday.
- The roof of reactor No. 4 is believed to be cracked.
- Japan suspends operations at Fukushima after a surge in radiation makes it "too dangerous for workers to remain at the facility."
- After a brief suspension, workers are allowed back on site.
- Japan's emperor makes a rare national appearance, officials say it is his first ever TV appearance
- Nuclear Regulatory Commission Chairman Gregory Jaczko indicates in remarks to a House committee that the US believed the damage at the Fukushima Daiichi nuclear power complex was even graver than Japanese officials had outlined in public.