Nuclear plant chief weeps as Japanese finally admit that radiation leak is serious enough to kill people

• Officials admit they may have to bury reactors under concrete - as happened at Chernobyl
• Government says it was overwhelmed by the scale of twin disasters
• Japanese upgrade accident from level four to five - the same as Three Mile Island
• We will rebuild from scratch says Japanese prime minister
• Particles spewed from wrecked Fukushima power station arrive in California
• Military trucks tackle reactors with tons of water for second day 

READ: Nuclear plant chief weeps as Japanese finally admit that radiation leak is serious enough to kill people