The odds of dying from a falling tree are still small but maybe not as small as they used to be. Here’s why—and what to do about it.

There are no exact statistics kept on the number of Americans killed by falling trees, so it’s difficult to know for sure if the problem has gotten worse, and if so, how much worse. You’re still far more likely to die driving to the trailhead than you are from a falling tree. But it turns out, these tragedies may not be isolated incidents.

“A lot of forests are suffering, whether it’s from pine beetles, other invasive species, or diseases that are causing trees to die off,” says the American Hiking Society. “The likelihood of trees falling down is a much lower possibility when there is a forest full of healthy trees, and there are a lot of unhealthy forests, especially in Colorado and California.”

In California and Colorado, there are forests with more dead trees still standing, known as snags. An unprecedented 129 million trees in California have died from drought and bark beetles since 2010. All of those dead trees, in addition to the deadwood that has accumulated over a century of fire suppression, can lead to the kind of massive, out-of-control wildfires that have plagued California in recent years.

These fires, of course, kill even more trees, and burn areas are particularly at risk for falling timber. In Colorado, there were 834 million snags as of 2017, or one in 14 trees—30 percent more than in 2010. Plus both the Pacific Crest and Colorado Trails go through extensive burn areas. The issue of dead timber is likely to worsen, due to the ongoing climate crisis.

Here are precautions you can take…