The types of microbes living in hot versus once-hot-now-cooled soil were, unsurprisingly, very different. What did surprise Shade is how quickly the microbial community in the recovered soil went back to looking like what it was pre-fire. This is good news; it means microbial communities are resilient in the face of massive upheaval. In the charred aftermath of a forest fire—to make a more macro analogy—lichens come first, then grasses, then shrubs, and then finally trees. But before that can happen, the same ecological succession plays out in miniature with the millions of microbes that live in soil.

What still puzzles Shade, though, is where those different microbes in hot soil came from. She hypothesizes the soil has a microbial “seed bank”—thermophiles aka hot-loving bacteria, for example, laying dormant for years as spores, just waiting for the off chance it’ll get hot. Soil may not look like much, but it is teeming with microbes with extraordinary abilities.

This seed-bank hypothesis makes sense for Peter Hartel, a soil microbiology and professor emeritus at the University of Georgia. He cites an example in that happens in a small scale in our own backyards: the compost pile. As banana peels and eggshells rot, they give off heat. And as it gets hot, the thermophiles take over, breaking down molecules that cool-loving bacteria cannot—which is why small compost piles that cannot retain heat are not as effective. Ordinary soil, says Hartel, “is just loaded with all these thermophilic organisms, which should have no business in it.” They’re just waiting their turn.

The blossoming of thermophilic organisms in coal-mine fires, which stay hot for much longer than a compost pile, could mean that such fires are fertile hunting grounds for rare microbes. A colleague of Shade’s at Michigan State has visited Centralia to look for a bacteria that fixes nitrogen, which could cut the use of nitrogen fertilizer in agriculture.

And others, like Madan Kharel, a biochemist now at the University of Maryland Eastern Shore, have gone to a different coal-mine fire in Kentucky to look for antibiotics and anti-cancer drugs. Lots of antibiotics originally come from bacteria, and big pharma companies have already gone digging through ordinary soil bacteria. “Our logic is what’s overlooked are those unique extreme environments,” says Kharel. His colleagues at the University of Kentucky, where the Ruth Mullins coal-mine fire work began, are now working on antibiotics isolated from bacteria at the site

Coal-mine fires are man-made disasters, long-lasting reminders of mining’s environmental destructiveness. How ironic then, if they could one day lead to a life-saving drug.