Here's why huge sinkholes open up in the ground out of nowhere

Sinkholes seemingly come out of nowhere, swallowing everything in their path, and generally looking like the apocalypse. But there is some pretty simple science to explain them. Following is the text of the video.

Sinkholes open up out of nowhere.

Swallowing cars, houses, and people.

What causes them?

If rainwater seeps into the ground with nowhere to drain ...

... it can start to build up underground, eating away at the dirt and rock

The hole grows until one day the dirt above it sinks, creating a sinkhole.

Sinkholes are more common in dissolvable terrain like gypsum, salt, and limestone.

Most of Florida has these types of terrain, and they're common throughout the world.

Humans can cause sinkholes, too.

Building massive sewer systems and mining can compromise the integrity of the ground.

The US geological survey tracks areas that could be susceptible to sinkholes.

But we never quite know where - or when - they might open up.

EDITOR'S NOTE: This video was originally published on June 22, 2016.