It happened Saturday afternoon at Pooch Pines Dog Park.
WPBF 25 News obtained cellphone video of the moments following the gruesome scene.
The pit bull was brought to the park by Fernando Matta Gonzalez and Estephany Marquez, according to the case report.
However, Jennifer Levy said minutes earlier she was leaving the park with her two dogs when one was attacked.
"When I bent down to clean-up after her, the pit bull came behind her," said Levy.
Levy watched in horror as a blue and white Pit Bull brutally mauled and killed her black and brown Yorkshire Terrier named "Jill."
"He shook her around like a rag doll and walked up and down the sidewalk with her inside his mouth before he finally dropped her," said Levy.
CAROLE SCHAPUIS TRIES TO CONVINCE YOU THAT ANY DOG COULD HAVE DONE THIS...
Carole Schapuis is the President at Pet Haven Animal Rescue in Loxahatchee. She owns two pit bulls and several years ago was attacked by another.
"Animals which are not neutered have a lot of built-up testosterone. This happened to be a pit bull. It can be any breed," said Schapuis.
No Carole, it didn't just "happen to be a Pit Bull". It's almost always the same type of dog. Don't give this woman or her 'rescue' any money; she clearly has an agenda with Pit Bulls.
Levy said she attempted to break the animals apart, while the owners stood by and watched.
However, the two people who brought the Pit Bull to the park insisted to investigators at Palm Beach County Animal Care & Control they did not own the dog.
Instead, they CLAIMED THEY'D JUST FOUND THE DOG earlier in the day and attempted to bring it to Peggy Animal Rescue League, but they would not accept it.
Yeah, when I find stray Pit Bulls I always head straight to the dog park with them!!!
Levy said while she is leery of Pit Bulls, this will not stop her from going to the dog park.
"A totally out of ordinary situation," said Levy. "If they're large dogs. Get them trained. Just be responsible. Not every dog is a candidate for a dog park."
The pit bull responsible for this brutal attack is being quarantined at Palm Beach Animal Care & Control.
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(WPBF - February 1, 2018)