Updated

Crews searching for any sign of six miners trapped for more than three weeks are "hoping a miracle could happen," a federal official told lawmakers Wednesday, while another hole was drilled to insert a robotic camera into the mountain.

But Kevin Stricklin, chief of coal mine safety for the U.S. Mine Safety and Health Administration, also said the Crandall Canyon mine could become a tomb if the miners are not found alive.

Three rescue workers digging through the rubble were killed Aug. 16 when their tunnel collapsed. Because of repeated seismic shocks, the mountain has been declared too dangerous to resume underground rescue efforts.

"There's a possibility that we may not be able to remove the miners from the mine," Stricklin told about a dozen state lawmakers at the Capitol, 120 miles north of the mine.

Federal mine officials volunteered to brief legislators on their rescue efforts. Members of the newly created Utah Mine Safety Commission were also on hand to ask questions. The commission was created by Gov. Jon Huntsman last week to decide whether Utah needs to begin regulating its mines, which it hasn't done since 1977.

No one knows whether the six miners survived the Aug. 6 collapse, which left reinforced roofs of mine tunnels mostly intact but blew out the walls, hurling chunks of coal like bullets and blocking passages. Oxygen levels in much of the mine are too low to support life.

A robotic camera, similar to one used to search the wreckage of the World Trade Center in New York in 2001, will be sent more than 1,500 feet down a seventh hole expected to be finished on Thursday.

"We're still hoping a miracle could happen. And we're going to keep doing it until we have no other alternative," Stricklin said.

By Wednesday evening, rescue workers had drilled about 1,400 feet into the mountain. They hoped to reach a depth of nearly 1,900 feet early Thursday.

Stricklin said rescue workers would continue searching for the men only as long as there is a possibility they're alive, the likelihood of which decreases each day.

He said mine co-owner Bob Murray will decide when the final hole is drilled. "He's the one paying for it," he said.

Stricklin said it costs about $1 million to drill each hole.

In Nevada, crews recovered the body of a miner killed during a cave-in at an underground gold mine, authorities said.

Curtis Johnson, 36, had been missing since early Tuesday, when the ground gave way at the Getchell Mine east of Winnemucca.

The Getchell Mine, a joint venture owned by Toronto-based Barrick Gold Corp. and Denver-based Newmont Mining Corp., is operated by Small Mining Development LLC, or SMD, an independent contractor based in Boise, Idaho, Barrick officials said.