I agree that the term Hero should be reserved for those who truly deserve it. Soldiers are doing their 'job', but it would be those that go above and beyond in extreme circumstances who would be classed as a hero. One example I can think of, is the helicopter pilot who went in to airlift out some troops and they came under heavy fire. He took a bullet between the eyes (his helmet saved him from being fatally wounded), yet he still managed to fly and take the soldiers out of harms way.
With regards to the miners, they have a dangerous job in the first place, accidents can and will happen - but that's the risk that they take.