Some residents have escaped with their lives. Some lie dead in the broken stone and twisted metal. Others are missing, their fates unknown.

Rescue workers wonder where to begin, or whether to begin, sifting through rubble. One wrong move and more of the building collapses, more lives possibly lost.

Instead of taking that chance, the rescuers send in a small helper. He tugs and shoves his way through the building’s still-intact system of water pipes.

Providing the rescuers eyes with a camera and ears with a microphone, the small helper locates survivors, tells the rescuers where to start digging.

This is one scenario that inspired MOCASIn 2, the small helper who crawls though pipes and searches for survivors of quakes, bomb blasts, or other disasters that can bring a building tumbling down.

The robot is the brainchild of Professor Edward Grant and the innovation of three of his N.C. State University students.

One of those students is Jason Cox, an N.C. State senior computer engineering major from Granite Quarry.

Cox, 22, son of Gary and Lugene Cox, describes MOCASIn 2 — Modular Observational Crawling and Sensing Instrument — as “basically, a robot that crawls through 6-inch PVC pipes.”

But the robot has the potential to be much more than a pipe-crawler, he says. And that’s why it and its inventors are garnering international attention.

Grant, a Scottish professor, is visiting the U.S. as part of a research program hosted by the U.S. Marine Corps.

He said the robot’s original inspiration was a conversation with a Marine Corps major who had worked on a rescue team after the 1995 bombing of a federal building in Oklahoma City, Okla.

“There was a great feeling of frustration because of the scene they were presented with,” Grant said. “They would have used any kind of man, animal, or machine they could have, if it would have saved lives.”

So, knowing that pipes stay intact when a building collapses, Grant began to think of a device that could make use of them and help in the rescue effort.

He pitched the idea at N.C. State and got a team of seniors working on it for their senior design project.

The result was a rough prototype. The next group of seniors — Cox, Steve Cottle of Wilmington and Brian Dessent of Durham — made it a working robot.

“They re-engineered the whole system and made a really exceptional job of it,” Grant said.

The three seniors designed the current robot, wrote the software that controls it, and built it for around $1,500, Cox said.

MOCASIn 2 moves “in inchworm fashion,” Cox said. It uses pads on either end to grab a pipe and cylinders in the middle to extend or contract, pushing and pulling itself along.

The robot can make turns up to 90 degrees and can even crawl up or down a vertical pipe, Cox said.

For now, it is equipped only with a camera. But future versions could include microphones to hear victims and speakers to talk to them.

“That’s useful, because, I believe people lose hope after they’re trapped,” Grant, the professor, said. “If they could hear anything, they might regain hope they’ll be rescued.”

Cox and the other seniors built it to run on an air-propulsion system because that won’t cause sparks if the robot wanders into a gas leak.

Completed in May, the robot sat on a shelf for several of months. But a recent appearance at a science exposition in Asheville has drawn it international attention.

Grant said he’s gotten requests from rescue units in Fairfax, Va., and Australia to use the robot in their operations. But he doesn’t want it to go public until it’s further tested and patented.

The media has jumped on the story as well. The robot and its inventors have have appeared on National Geographic’s Internet site and are in this month’s Wired magazine.

The British Broadcasting Agency and Canadian television have covered it, and CNN filmed a piece to be included in a science and technology program.

Though they realize the robot’s potential usefulness to rescuers after a catastrophe, Cox said, the N.C. State students didn’t expect such hoopla over their senior project.