Can you hear me now?
Mine communications are complex, slow and unreliable. The solution to keeping miners safe, and rescuing them when disaster strikes, might just be in their hands already.
Acid drainage from surface coal mining site, North Lima, Ohio.
As coal energy loses market share, major U.S. coal companies are filing for bankruptcy. One multi-billion-dollar question: will taxpayers be forced to pay for cleaning up abandoned mines?
The Hazelwood fire burned for 45 days in 2014.
AAP Image/Incident Control Centre Hazelwood
Two years after Morwell was blanketed in smoke from the Hazelwood fire, environmental charges have been laid against the mine's operators. But the process should be more open and democratic - and quicker.
An open-cut coal mine in the Hunter Valley.
Methane is a stronger greenhouse gas than carbon dioxide, and Australia's coal mines are a major source.