WASHINGTON - The method of mining used at the Utah mine that collapsed Monday, trapping six miners, has a history of being disproportionately deadly, according to federal safety studies. It is "the most dangerous type of mining there is," said Tony Oppegard, a former top federal and state of Kentucky mine safety official who is now a private attorney in Lexington, Ky., representing miners. The reason the practice is used is that it pays off: The last bit of coal taken from pillars is pure profit, Oppegard said. Plus, if someone violates rules during pillar removal and there is a...