The latest update from IAEA :
" Japanese authorities have informed the IAEA that a fire in the reactor building of unit 4 of the Fukushima Daiichi nuclear power plant was visually observed at 20:45 UTC of 15 March. As of 21:15 UTC of the same day, the fire could no longer be observed.
Fire of 14 March
As previously reported, at 23:54 UTC of 14 March a fire had occurred at unit 4. The fire lasted around two hours and was confirmed to be extinguished at 02:00 UTC of 15 March.
Water level in unit 5
Japanese authorities have also informed the IAEA that at 12:00 UTC of 15 March the water level in unit 5 had decreased to 201 cm above the top of the fuel. This was a 40 cm decrease since 07:00 UTC of 15 March. Officials at the plant were planning to use an operational diesel generator in unit 6 to supply water to unit 5.
The IAEA continues to liaise with the Japanese authorities and is monitoring the situation as it evolves."