Day 1: Monday, Aug. 6
A seismic event registering 3.9 on the Richter scale is recorded by the University of Utah Seismograph Stations in the area of the Crandall Canyon Mine at 2:48 a.m.
About an hour later, an Emery County sheriff's deputy receives a call about a mine collapse.
Rescuers attempt four separate ways to access six miners believed to be trapped 1,800 feet underground.
Day 2: Tuesday, Aug. 7
Another seismic "bump" collapses part of the tunnel, shutting down underground rescue work. "We are back to square one underground," mine owner Bob Murray says.
During a news conference, Murray offers updates but also attacks unions and some news media outlets.
Atop the mountain, workers clear a road and begin drilling a 2-inch-diameter 1,800-foot vertical shaft.
Day 3: Wednesday, Aug. 8
Drilling efforts on the mountain above the mine make progress, cutting more than halfway to the chamber.
The names of the trapped miners are learned. "They'll walk out of there," one family member says.
Utahns pray at vigils and celebrate Mass for the miners and their families.
Day 4: Thursday, Aug. 9
Descending 1,868 feet, the drill boring a 2-inch hole breaks through into a chamber at 9:47 p.m. A microphone picks up no human noise. Oxygen-level samples from the mine vary.
A high-resolution camera is flown in as another drill grinds steadily toward the collapsed area.
Communities in Utah's coal country rally behind families of trapped miners.
Day 5: Friday, Aug. 10
As work continues in the mine tunnels, federal mine officials say the drill may have missed the chamber where the trapped miners are.
The families of three of the trapped miners ask people to "light a candle and raise a prayer for our miners."
Day 6: Saturday, Aug. 11
A second, larger drill punches an 8 5/8-inch hole into the mine about 3 a.m. After quieting their machines, rescuers tap on the drill steel but hear no response.
A camera is lowered, and rescuers later announce they have found "survivable space" in the area where the drill broke through but no trace of the miners. Water and other obstacles hamper the camera.
LDS Church members in the sister towns of Huntington, Cleveland and Elmo begin a
24-hour fast to show support for the miners.
Day 7: Sunday, Aug. 12
Mine officials announce they will drill a third hole between the cavity where the miners were working and an exit where they could have fled to safety.
A video camera is dropped into the second completed borehole, which now has a steel liner. This time a horizontal lens finds a tool belt and chain from a conveyor belt but still no sign of the miners.
Day 8: Monday, Aug. 13
A new roadway and clearing are cut on top of the mountain for the third drill and its rig. The 8 5/8-inch borehole is directed toward an area with good air at the back of the mine where the trapped miners could have retreated.
Day 9: Tuesday, Aug. 14
The mining company releases video showing miners clearing and shoring up the collapsed tunnel.
The third drill hole proceeds about halfway to its target area.
Day 10: Wednesday, Aug. 15
Devices called geophones, placed on the mountain, detect "noise," or vibrations — offering hope that the trapped miners may be alive.
Work begins on a fourth large borehole, targeting the area of the vibrations.
Images from the third drill hole also offer good news, showing a chamber with breathable air.
Community residents host a concert to honor the missing six miners and those working to rescue them.
Day 11: Thursday, Aug. 16
As work continues inside the mine, video images from the third borehole atop the mountain show no sign of the miners.
Three rescue team members are killed or mortally injured, and six others injured when another seismic bump inside the mine buries the men in coal and debris. The 6:35 p.m. bump registers as a 1.6 magnitude seismic event. Ambulances and medical helicopters rush to Crandall Canyon and during the evening transport the injured to hospitals in Price, Provo and Salt Lake City.
Work underground halts, while the drilling efforts above continue.
Day 12: Friday, Aug. 17
The underground rescue operation is suspended indefinitely.
Utah Gov. Jon Huntsman Jr. says the Crandall Canyon Mine collapse has gone from a tragedy to a catastrophe. "These men died as heroes," he says of the rescuers killed on Thursday.
Huntsman says he intends to have a panel conduct the state's own investigation into the disaster, parallel to the expected federal inquiry, to determine if Utah should have more control over mine safety.