BRAIDWOOD, Ill. (CBS) — The tremendous earthquake in Japan has triggered a state of emergency at two nuclear power plants in that nation, and thousands of residents within six miles of the plants have been evacuated.

The worst case scenario: a potentially catastrophic nuclear meltdown. Workers are trying to prevent that from happening.

When the electric grid that powers the Fukushima Daishi plants crashed in the quake, diesel generators kicked in. Then at least one of the backup generators failed. That crippled the vital cooling system that pumps thousands of gallons of water through one of the plant’s six reactors.

Heat began building, and so did pressure in the form of steam.

“They’re doing what they can to cool the core,” says Carlo Segre, from the Illinois Institute of Technology.

Mildly radioactive steam is now being vented into the air to keep the reactor from “melting down” and spewing huge amounts of highly radioactive steam.

Now a similar problem has developed at a second Fukushima plant. The race is on to stave off another possible catastrophe.

Closer to home, residents who live in suburban Will County were asked whether they fear something similar could happen here. A nuclear plant in Braidwood provides power.

“That’s always a possibility,” Joe VanDuine told CBS 2’s Mike Parker. “If it happens, it happens, you know. There’s not really much we can do, except move.”

Jerry Kiely of Braidwood admits:  “Actually, I think it’s a little bit dangerous. I really do.”

That said, Kiely says he sleeps at night.