Coal is a tough industry in the market right now, and a lot of small companies are faltering. James River Coal has already stumbled into bankruptcy; Walter Energy (WLTGQ) might be next to keel over.

In this "Digging for Value" video, Fool energy and materials analysts Joel South and Taylor Muckerman talk about liquidity issues among coal companies and how if prices and demand don't improve within the next few years it's possible debtors won't offer more money, which means these businesses would have to halt operations.