Deadly mine collapses have recently occurred in West Virginia (January 2007, two miners killed); Russia (March 2007, 106 miners killed); Utah (August 2007, six miners and another three from the rescue team killed); Colombia (October 2007, 24 miners killed); and many other places. Locating trapped miners as soon as the collapse occurs will save lives and avoid dangerous searches in the wrong places. © 2009 Society of Exploration Geophysicists.