At approximately 6:00am, a loud explosion was heard from within the 
power station. Afterwards, it was confirmed that the 4th floor rooftop 
area of the Unit 4 Nuclear Reactor Building had sustained damage.

After usage, fuel is stored in a pool designated for spent fuel.

Plant conditions as well as potential outside radiation effects are 
currently under investigation.

TEPCO, along with other involved organizations, is doing its best to 
contain the situation. Simultaneously, the surrounding environment is 
being kept under constant surveillance.