HUNTINGTON — Drilling is scheduled to begin this afternoon for what may be the final attempt to reach six miners trapped in the Crandall Canyon Mine.

It comes after no signs of life were detected inside the last 8 5/8-inch hole to be drilled through a mountain, the federal Mine Safety and Health Administration said this afternoon.

"No pictures or air samples were obtained from bore hole No. 5 as the hole became plugged with mud," MSHA said in a brief statement this afternoon.

The sixth hole will be the final one, the mine's owner has said.

"This is the last hole," mine owner Bob Murray said Wednesday night. "If we don't find anybody in that hole, there is nowhere else that anyone ... would know where to drill anymore holes to try to find these trapped miners."

Rescuers are drilling 1,700 feet through a mountain to a cavern where the miners were last believed to be. The drill is expected to break through Saturday, and it may bring a heartbreaking and frustrating halt to the frantic search for trapped miners Don Erickson, Kerry Allred, Luis Hernandez, Brandon Phillips, Carlos Payan and Manuel Sanchez. The men may be entombed inside a mountain.

Rescue efforts trudge along "until we're assured there's no life, and we can't get the folks," said Jack Kuzar, a regional director for MSHA.

A fifth hole that punched through 1,586 feet of mountain Wednesday went only 6 inches into the cavern before hitting a coal bed.

"It was within 6 inches of the roof. There was no one going to get in that area," Kuzar said Wednesday.

Air samples were being taken and a camera was lowered Wednesday night in an attempt to glean information about the miners' fate.

Four previous drilling operations have shown no sign of the miners, who have been trapped since a 3.9 magnitude seismic event collapsed the section of the mine where they were working Aug. 6. In addition, air samples taken from the drilled holes have shown that oxygen levels in those areas of the mine are insufficient to sustain human life.

Families react

Federal authorities met with some of the families of the trapped miners this morning. They left without commenting to reporters. The families have urged the rescue effort to continue and said they would ask Utah Gov. Jon Huntsman Jr. to exert some pressure.

"They're hoping that Mr. Murray will retract his statement that he won't retrieve them if they did, in fact, perish, that they'll find some way and utilize some method, regardless if it takes three months for seismic activity to stop," family spokesman Sonny Olsen said Wednesday. "They want some method to go down and get their family members."