By Rachel Leigh| January 11, 2013 at 4:35 PM EST - Updated July 25 at 10:30 PM
RIVIERA BEACH, FL (WFLX) - Authorities say it is one of the worst cases of animal cruelty they have ever seen - a live, healthy dog being set on fire. Now, the search is on for answers in Riviera Beach to find out how a pit bull terrier spent the painful final moments of its life.
"I heard a 'whoosh' noise like that," said Diana Perez Cruz, talking about the sound of ignition right out side her back door.
On fire, authorities say, was a dog -- a young pit bull. "And it was yelping, like begging," said Cruz. "And when I looked out the door, that's when I saw like a bonfire. The fire was all the way up."
Cruz says flames shot all the way up from the animal into the trees along the alley at the end of West 27th Street in Riviera Beach.
Investigators say someone doused the dog in gasoline and set it on fire. "The most unexplained, unimaginable, I can't even begin to understand why somebody would do this," said Captain Dave Walesky of Palm Beach County Animal Care & Control.
Walesky says he has never seen a cruelty case quite like this. "He would have to be a very sick and twisted individual to take a live healthy animal, tie him to a fence, pour gas on him and light him on fire," he said. "It's somebody that we don't need around."
Nearly four days after Monday night's incident, and there are still no known suspects, and authorities are not sure who the dog belonged to. The animal had no collar and no micro-chip. The person responsible could face up to five years behind bars. "You know, that's a person without a heart," said Cruz.
Authorities are canvassing the area handing out flyers to people who may have seen or heard the incident unfolding. Anyone with information about this incident is asked to call Palm Beach County Crime Stoppers at 1-800-458-TIPS.