A robot sent to explore the submerged ruins of Japan's Fukushima nuclear plant is offering a new look at the damage from one of history's worst nuclear disasters. The device nicknamed "Little Sunfish" found melted clumps of material that could be the fuel debris it was sent to locate, according to updates Friday.

After an earthquake struck near Japan on March 11, 2011, a tsunami spurred by the quake hit the nuclear plant, damaging generators and causing three nuclear meltdowns and the subsequent release of radioactive material. No radiation-related deaths have been reported, but nearly 100,000 homes had to be evacuated in the aftermath of the disaster.

Six years later, the homes remain deserted. But underwater robots could be the key