Texas got slammed by 14 inches of rain overnight and it's leading to 'unprecedented' flooding

The Houston area was pummeled with rain last night.

Over a 12-hour period, more than 14 inches fell across certain parts of Texas, according to the National Weather Service. Here are the areas that got hit hardest, where there are also flash flood warnings in effect:

NWS

Houston Mayor Sylvester Turner called the flooding "unprecedented," USAToday reports. 

As much as 21,000 square miles of land is covered in the flash flood warning, extending west toward San Antonio and Austin. And it's not over just yet, with more rain coming soon across the south: 

Here's some of the damage that's happened so far, as seen in Houston. People have had to evacuate their houses and apartments in search of dry shelter. 

David J. Phillip/AP

With floodwaters high, it's close to impossible to take cars out on the road, and public transportation in Houston has been shut down.

David J. Phillip/AP

The dump truck below is braving the more than a foot of standing water.

David J. Phillip/AP

Some have even taken to alternative modes of transportation: 

The Texas Department of Transportation is urging people to stay off of the roads, especially in Houston: