Relatives of six miners trapped deep inside a Utah coal mine are holding out hope the sixth — and last — borehole will provide the miracle they've craved for more than two weeks.

Other holes drilled into the Crandall Canyon mine have failed to reveal signs of life. The sixth hole is to be drilled Thursday into an area where the miners were last believed to have been working.

"This is the last hole," mine co-owner Bob Murray said at a news conference Wednesday night. Drilling it, he said, will "bring closure to me that I could never get them out alive."

But Jackie Taylor, whose daughter Lacee dates one of the six men missing since an Aug. 6 cave-in, said relatives and friends are insisting that more be done.

She issued a plea Thursday for the rescue effort to continue, even though three men died trying to tunnel toward the miners.

"We are so appreciative to all of the rescue members and their families. Don't get us wrong, we are so appreciative," Taylor told NBC's "Today." "Our love and our prayers go out to all of their family members. But our family members are still under there. They're underground. We need that closure in our lives also."

Punching through the fifth borehole Wednesday, rescuers found only a 6-inch void in the mine 1,500 feet down, federal officials said.

No noise was heard from the hole after a microphone was lowered and workers banged on the drill steel, said Jack Kuzar, a district manager for the Mine Safety and Health Administration. A video camera had not yet been put down the hole, nor had oxygen readings been measured, Kuzar said.

Attempts to tunnel through the broken mine shaft toward the miners were halted after a second cave-in killed two miners and a federal safety officer. Six others were injured.

Sonny J. Olsen, a lawyer and spokesman for relatives of the miners, said the families don't want the search to end until the men are found.

"Regardless if it takes three months to wait for the seismic activity to stop, they want some method to go down and get their families," Olsen said.

Taylor, who said she had a shouting match with Murray during a Monday night meeting with families, said the mine owner is reneging on his promise to return the men to their families dead or alive.

"I didn't desert anybody," Murray told The Associated Press. "I've been living on this mountain every day, living in a little trailer."

Families are also angry at Murray over the suspended tunneling and the decision against digging a hole big enough for a rescue capsule to be lowered. Other critics and mine experts have questioned whether mining should have been conducted at Crandall Canyon at all because of the potential for collapses.

Murray said it's up to federal officials to decide when the mine can be sealed after it completes its investigation.

He said he would not resume mining at the Crandall Canyon mine. "I can tell you right now, we are not going back into that mountain," he said.

If investigators can't get to the point of the collapse's origin, Kuzar said, "we will never really know what happened."

Most workers at Crandall Canyon have been given jobs at two other mines in central Utah's coal belt, although a small crew remains at Crandall Canyon, Murray said.

The collapse that trapped the miners is believed to have been caused by settling layers of earth bearing down on the walls of a coal mine. The force can cause pillars to fail, turning chunks of coal into missiles. The unpredictable and dangerous phenomenon is known by miners as a "bump."

"Had I known that this evil mountain, this alive mountain, would do what it did, I would never have sent the miners in here," Murray said earlier. "I'll never go near that mountain again."

Murray has insisted the collapse was caused by a natural earthquake, but government seismologists say the collapse itself is what caused the ground to shake, registering a magnitude of 3.9. Since then there have been several other bumps.