SAFETY HARBOR, Fla. (WFLA) – She stabbed their family dog to death.

When “Buster” broke loose from her house on West Gate Drive in Safety Harbor and went on the attack, a teenager stopped the vicious animal with several deadly thrusts.

Severely bitten and being tended to by paramedics, 45-year-old Heidi Cooper, a victim of the dog bite, laid on her back, IVs running.

Pinellas County deputies tell us Buster attacked two other pit bulls. Cooper and her two teen girls, 14-year-old Meaghan Tokay and 22-year-old Sierra Wilson, tried to get him to stop, but he turned his jaws on them.

Cooper and Tokay suffered multiple puncture wounds and lacerations. Wilson suffered minor scratches.

Another neighbor ran to help.

“Heard screams for help and proceeded up the road, up the street here and just seen a woman that was frantic, yelling, ya know, ‘stay back. Stay back. The dog will attack,’” said Joe Goulart.

Peter Peterson watched the aftermath of the attack, including EMS crews taking the three victims.

He’s very careful when he sees Buster out.

“I’ve always been leery of it. Pitbull reputation. I keep my wife in the house when it’s out. They do keep it tied at the front but it has gotten loose several times,” said Peterson.

Family friend, Nikki Cagen, tells News Channel 8 Buster actually belongs to her boyfriend, away in the military.

“I was completely shocked. I’ve never heard anything, especially this dog. He was the sweetest, sweetest dog ever. I would come in the house. He would come sit on my lap like a little puppy,” said Cagen.

All three victims have non-life threatening injuries.

Cooper got it the worst. She has several, severe bites.

Deputies responded to this house a month ago for another bite from the same dog.

A family member told deputies the dog was normally kept in a separate room because he was known for being aggressive.