Reports are coming in that there has been an explosion at the Fukushima Daiichi nuclear power plant's No. 3 reactor. Officials had warned about the possibility of an explosion due to a build-up of hydrogen as efforts continued to cool the reactor with seawater.
Reuters reports that officials are unceratin at this point if the explosion has only affected the outer concrete wall as happened at the weekend, or if there is an uncontrolled leak of radioactivity. At present it seems like the containment vessel in intact, but we'll keep you posted as we find out more.