"Katrina the ballerina dances in the sky
Destroying everything in sight low and high"

This was a clever and unique line I thought, good way to open the piece up.

"Katrina twirls like a tornado
Until everything looks like tomatoes"

This rhyming here to me was very forced, and it didn't give off the imagery I expected. I just thought the "tomatoes" part didn't fit and was not relevant at all.

"Katrina dances over water and land
Makes buildings fall over into sand"

Good rhyme here, I like your wording, it clearly states what is going on and gives off imagery.

"When Katrina dies we all cry"

The way you worded it here made it sound like we cry because we miss her. I think you need to clear things up a bit.

"We lost things we loved
To the streets it is shoved"

Instead of talking about "things" lost what about people lost? That is more important. I felt this ending to be a little weak and this was a very short poem. Maybe try going in fuller detail and elaborating more.

4/5 from me, take care and may God Bless You and your family forever.