As many as 80 people are thought to have been killed in the US after a hurricane battered the Gulf coast.
It's thought all of those deaths may have happened in Harrison county in the state of Mississippi, which was the area hit worst by Hurricane Katrina.
Katrina also damaged the city of New Orleans, with hundreds of thousands of people leaving before it arrived, and many have nowhere to go back to.
It's been reported that the hurricane has caused up to $25bn (£14bn) damage.
It's thought the flooding could keep people who live in New Orleans away from their homes for weeks and maybe even months.
The mayor of New Orleans - in the state of in Louisiana - says around 80% of the city is under water after heavy flooding.
The hurricane has calmed down a bit now, but is still expected to cause lots of trouble when it gets to the states of Tennessee and Ohio.
Tornado warnings are in place in some of those areas.
As it approached the US Katrina was a category five storm, which is the most powerful there is, but before it hit land it became a little weaker.
It actually passed just to the side of New Orleans, so although the city was badly damaged, things could have been much worse.
The hurricane also caused lots of damage in south Florida on Friday, killing nine people.
It was really scary. We had to move to Washington as soon as we heard that it was coming. My uncle got all the stuff from our house and we've moved into a small hut at the edge of town. When the twister was over our dad called and said that 80 dead people were brought into the hospital where he works and more are going to arrive tomorrow!!
George, 15, New Orleans
It was dreadful and it was so frightening. I had to hide in the basement.
Melissa, 11, Florida
I've recently been to a part of Florida badly affected by last year's hurricane Charley. The devastation is the sort of thing which you only believe when you see, it's shocking.
Francesca, 16, Sutton