WATCH: Shock wave visible during explosion at Japan nuclear plant (VIDEO)

Shock wave at :47 in

Japanese TV showing walls at power plant have crumbled

“Not clear if the damaged building housed the reactor which officials fear is facing a possible meltdown”

Explosion heard at Japan nuclear plant — “High possibility of meltdown” for reactor No. 1: Government

“FLASH: Explosion heard at TEPCO’s Fukushima Daiichi plant around 0630 GMT – media” — Reuters, March 12, 2011 at 12:00 am EST