Here's What Happens When a Sinkhole Opens Up

The maw of a 120-foot wide Spring Hill, Florida sinkhole threatened to swallow homes in a quiet neighborhood after sneaking up on a group of neighbors on a Sunday afternoon. The terrifying 30-foot-deep sinkhole opened up in front of witnesses who said it emerged with no warning at all, according to neighbors who spoke to local station WTSP. Neighbor Margaret Helmick saw what happened firsthand, ABC said.

Out of nowhere the earth just went straight up in the air and exploded up in the air.

At least one woman had to be evacuated from her home in Hernando County, Florida, ABC reported. Linda Fisher, whose house neighbored the sinkhole, was out of town when the earth opened up. She told WTSP she had to leave her house overnight.

It's devastating. You don't expect it.

Her daughter Michelle Parisik said the front of her mom's house was "on a ledge hanging, pretty much."

Sinkholes are really common in the state, and the Southwest Florida Water Management District calls them "one of the predominant land forms in Florida." Cool. They occur when a soft or porous underground surface — one that water can flow through — is gradually dissolved, according to USGS. But though the dissolution of the ground may be gradual, the opening of the sinkhole itself often isn't.

USGS also happens often in Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania, but they can happen elsewhere, too. Usually they don't sneak up on people like this one did, instead opening up as a small hole and gradually getting bigger, but it can happen, the agency says. The rapid ones, according to the Florida Geological Survey (FGS), are called collapse sinkholes and usually show up in areas with "clayey sediment." Smaller ones are called solution sinkholes, which open up more slowly and less dramatically in sandy places.

About 300 sinkholes have opened in Florida since 2010, ABC reports — and those are just the ones we know about. The FGS says it's not an illusion: sinkholes really have started forming more often recently. That's been influenced by periods of drought mixed with heavy rain; more land and road development; retention pumps; and water management that changes the way groundwater flows beneath the surface.

Usually there isn't video of big sinkholes emerging because it often happens so quickly, but here's security camera footage of one sinkhole that opened up underneath a car museum in Kentucky in February. That sinkhole ate eight cars, but nobody was hurt.

Image: ABC, Getty, Giphy