A magnitude-9.0 earthquake and the ensuing tsunami have stricken Fukushima No. 1 and No. 2 nuclear plants, triggering a regional nuclear crisis. The following is the latest known status of all affected reactors, provided by Kyodo news agency on Wednesday.

Fukushima No. 1 plant

-- Reactor No. 1 -- Cooling failure, partial melting of core, vapor vented, building damaged Saturday by hydrogen explosion, seawater being pumped in.

-- Reactor No. 2 -- Cooling failure, seawater being pumped in, fuel rods fully exposed temporarily, vapor vented, building damaged Monday by blast at Reactor No. 3, damage to containment vessel on Tuesday, potential meltdown feared.

-- Reactor No. 3 -- Cooling failure, partial melting of core feared, vapor vented, seawater being pumped in, building damaged Monday by hydrogen explosion, high-level radiation measured nearby on Tuesday, plume of smoke observed Wednesday, damage to containment vessel likely.

-- Reactor No. 4 -- Under maintenance when quake struck, fire Tuesday possibly caused by hydrogen explosion at pool holding spent fuel rods, pool water level not observed, fire observed Wednesday at building housing reactor, no water poured in to cool pool.

-- Reactor No. 5, No. 6 -- Under maintenance when quake struck, temperature slightly rising in spent fuel pool.

Fukushima No. 2 plant

-- Reactor No. 1, No. 2, No. 4 -- Cooling failure, then cold shutdown.

-- Reactor No. 3 -- Cold shutdown.