In late December 2015, a landslide swept across an industrial park in the southern Chinese city of Shenzhen — one of several large, deadly landslides to hit China over the past five years. A 20-story-high mountain of construction waste collapsed and tumbled across an area the size of 60 football fields, burying factories and workers' dormitories.

Landslides are common in the United States as well. These natural disasters — masses of rock, earth and debris crashing down a slope — occur in all 50 states and territories and cause about 25 to 50 deaths a year according to the Centers for Disease Control and Prevention (CDC). They are most common in mountainous terrain, according to the Virginia Department of Mines, Minerals and Energy (DMME).

“People who live in mountainous terrain definitely need to be careful how they develop their land,” says Anne Witt, a geologist with DMME. “One thing we tell landowners a lot is to watch where the water goes. Make sure the drainage is good. Because it’s really water that can trigger landslides.”

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What causes landslides?

Landslides are caused by disruptions in the natural stability of a slope, Witt says. They can follow rains and droughts, earthquakes or volcanic eruptions.

Mudslides, aka debris flows, are a common type of fast-moving landslide that usually start on steep slopes. They develop when water accumulates in the ground rapidly, resulting in a surge of water-saturated rock, earth and debris. They’re more common in areas where wildfires or people have destroyed trees and other vegetation on slopes, making them more vulnerable to landslides during and after heavy rains.

Besides the obvious threat of injury from the slide itself, slides can pose dangers due to broken electrical, water, gas and sewage lines, along with blocked roadways and unsafe drinking water in the days immediately afterward.

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How to protect yourself

Start by learning whether any landslides have occurred in your area and what your risk is. To find out, contact your area’s local planning department or the department of natural resources. Here are some other tips to help stay safe, courtesy of the CDC and Witt.

Plan ahead. Develop an emergency evacuation plan for your family and have an emergency kit at the ready.

Listen for public alerts. Turn on the radio or watch TV for warnings during unusually heavy rainfall or a natural disaster.

Pay attention to natural warning signs of an approaching landslide, such as flowing mud or a rapid increase or decrease in the water level on a stream or creek. “If you’ve got rain greater than 5 inches in less than 24 hours, watch out,” says Witt. “This will often trigger debris flows. Areas with slopes greater than 30 degrees — which is pretty steep — that’s where landslides tend to originate.”

Check with the park service if you’re hiking on steep slopes after heavy rains. Landslides don’t really sneak up on you, Witt says. “They’re pretty obvious. If you’re going hiking, call ahead, call the park service to see if they have issued any landslide warnings or closed any trails.”

Watch out for subtle signs the ground is shifting. Pay particular attention to tilted trees, telephone poles, fences and walls as well as new patches of bare earth on hillsides. “If you see horizontal or vertical cracking inside your house, if your doors and windows don’t shut properly, that could mean things are moving,” says Witt. “Tilted trees or trees that have a steep curve have corrected themselves due to sliding. This can be a warning sign, too.”

Listen for rumbling sounds. These might indicate an approaching landslide or mud flow.

Evacuate if you have time. If not, try to reach higher ground away from the landslide’s path. If rocks and debris are tumbling toward you, run for shelter and take cover inside under a sturdy desk or table if possible. “Getting out of the way is all people can really do,” Witt says.

Curl into a ball and protect your head if you can’t escape.

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Safety after a landslide

  • Stay away from the area until authorities say it’s safe to enter it. Flooding or additional slides can occur after the initial landslide or mud flow.
  • Check for injured or trapped people near the area if you can.
  • Listen to the radio or TV for emergency information.
  • Report broken utility lines to your local utility company.
  • Consult an engineer with soil engineering expertise for advice on what you can do with your property to avoid future landslides.

Related: How to Survive an Avalanche

Steve Evans, MA, is an award-winning journalist with more than 20 years experience in daily news, investigative, health and business journalism. Among other jobs, he has served as managing editor of the Central Virginia Newspaper Group, as a senior writer for SNL Financial and as a staff writer for The Progress Index and the Richmond Times-Dispatch.