HUNTINGTON, Utah – As the search for six trapped miners entered its fourth week, bad weather postponed longshot efforts to drop a robotic camera deep into a Utah mountain to find the missing men.

Federal safety officials told the miners’ families the weather also delayed drilling on a seventh borehole, said Colin King, the families’ attorney.

“Not much happened due to the very difficult, muddy and rocky conditions up there,” Mr. King said after an attempt last night to put the robotic camera down a previously drilled borehole.

Safety officials also cited unspecified technical problems for the delay, he said.

The camera is similar to one used to search the wreckage of the World Trade Center after the 2001 terrorist attacks in New York City. It can travel 1,000 feet and take images from about 50 feet away with the help of a 200-watt light.

It was not known for certain if the camera would move past rock and other debris before gaining access to the mine. Still, Mr. King said rescuers planned to make another attempt to lower the camera once the weather cleared.

“There is no indication they are giving up,” he said. “I think they are genuinely anxious to see if this robotic camera gets some results for them, and they did put it down the hole enough to see this is going to work.”

The six miners have not been heard from since the Aug. 6 cave-in, which filled a mine tunnel with rock and coal in the area where the men were working. No one knows whether the men survived the collapse.

Mine officials and federal regulators have worked unsuccessfully to locate the men, drilling a half-dozen vertical holes into the mountain in hopes of finding signs of life.

Horizontal tunneling through the tons of debris inside was halted Aug. 16 after a second cave-in killed three rescuers, including a federal safety inspector, and injured six others.

Yesterday, Emery County sheriff’s dispatch tapes released to The Associated Press revealed that a seismologist was the first to notify authorities of a possible problem at the Crandall Canyon mine.

University of Utah seismologist Walter Arabasz made his call four minutes before mine officials called the sheriff’s office seeking an ambulance.

The dispatch tapes showed that from the earliest moments scientists suspected the shaking came from a mine collapse, not a natural earthquake, as mine co-owner Bob Murray has maintained throughout the ordeal.

“Just from the general character of the seismic event, it looks like it might be a coal-mining event,” Mr. Arabasz said on the tapes.

The first 911 call came at 3:47 a.m. from Mr. Arabasz in Salt Lake City, 120 miles north of the mine. At 3:51 a.m., a mine employee called for an ambulance.

“We had a big cave-in up here, and we are probably gonna need an ambulance. We’re not for sure yet because we haven’t heard from anybody in the section,” a voice identifying himself as Mark Toomer told a 911 dispatcher. “But we’re mostly likely going to need one up here.”

Mr. Arabasz told the dispatcher the seismic event registered as 4.0 magnitude at 2:48 a.m., and it was 3.1 miles west-southwest of the mine entrance. The severity of the event was later revised to 3.9 magnitude.