(What is the government saying about the cause of the explosion?) It's thought to be from a pocket of methane gas. As one digs lower, methane becomes more common and the heat is more intense. When you combine those and coal dust and the electricity that's used, methane explosions are actually quite common, even in Ukraine. (This is the same as that of an explosion in Virginia a couple years back. in Ukraine, how far underground were those miners?) The two brought out early Monday morning were at 750 meters, the other 21 brought up were at two-thirds of a mile down. We saw another such accident in May that caused the deaths of 10-plus miners. After that, this mine was actually declared unsafe. But it seems there's doubt about whether this mine stopped mining for coal. (Is it known whether these miners have any emergency equipment?) It's unknown. Ukraine has been investing in better equipment, but they have a huge amount of catching up to do. (What is the place of coal in the Ukrainian economy?) It's increasing. Ukraine is seen as divided between east and west, the west is agricultural and the east is more industrial. the other big point is Russia, and Ukraine is very reliant on Russian natural gas and other energy so Ukraine thinks it needs to rely more on its own resources, such as coal. And this plays into, by extension, the rest of Europe's security as well. (What are officials saying about how long the miners could survive down there?) Officials said things are getting critical and at least a dozen miners are still unaccounted for. Things will be looking quite bleak now.