Despite the horrific situation of the six Utah miners trapped, and the agonizing worries besetting their families, there have been remarkable true-life tales of survival, even in the toughest of mining disasters.

Randy McCloy Jr. managed to live for 41 hours after the Sago Mine explosion in West Virginia in 2006. His 12 co-workers died, but for some reason McCloy survived the blast and carbon monoxide exposure and was able to leave a hospital after nearly three months of treatment.

Decades earlier, seven men were trapped underground for nine days and emerged alive after surviving the Springhill Mine disaster in 1958, one of the worst in North American history.

In that disaster, 174 men were working the mine when there was a "bump," or underground earthquake, that killed 75 of them, according to a book titled "Last Man Out: The Story of the Springhill Mine Disaster" by American writer Melissa Fay Greene.

Ninety-nine men were rescued during a lengthy rescue effort in the Nova Scotia mine that was the first such event to be televised. Of those individuals, 12 were trapped for six days, and seven men were trapped for nine days. Greene interviewed all 19 of these survivors for her book, along with miners' wives and widows.

The event was chronicled in a song by folksinger Peggy Seeger titled "The Ballad of Springhill." Later it was performed by folksingers Peter, Paul and Mary and the Irish rock group U2.

In 1906, a mining tragedy of enormous proportions occurred at the Courrieres mine in France that killed more than 1,099 people — including child workers. About 600 managed to escape.

However, 13 people who were trapped for 20 days survived and were rescued.

There is no way to predict what the outcome will be in any mining disaster because there are so many variables, according to David Kameras, communications coordinator for the United Mine Workers.

"It's hard to say how long someone can stay alive," he said. "It may not apply in this (Utah) case, but often air quality is a major factor."

It can be disastrous if mine workers are not shielded from toxic air because of methane gas leaks, but Kameras is quick to note this is typically not something that is found in mines in the Western United States.

"Obviously, depending on how a roof fall or collapse takes place, that will determine how much oxygen is available. We also don't know what kind of survival equipment these people had on them, and that clearly would be a factor, too."

Other variables would be what injuries the miners might have suffered. "Let's also not forget these would be total blackout conditions. They would see nothing, there would be disorientation in terms of geography and time. They would have flashlights with limited battery power that they would likely try to conserve."