Robot probe no. 2 dies while exploring a Fukushima reactor

The second robot Tokyo Electric Power Company (TEPCO) sent into Fukushima's unit 2 reactor also failed to finish its mission. Now, it's the machine's left crawler belt that stopped working (PDF) altogether, forcing TEPCO to cut off its tether and to leave it inside. Toshiba designed these scorpions specifically to examine Unit 2's condition and to locate the melted uranium fuel within. The information would help Tepco figure out the best and safest way to clean the fuel up. The power company still isn't sure whether the robot's crawler belt stopped working due to the radiation levels inside or due to all the debris the first machine wasn't able to clear.