Police are searching for a pit bull that attacked and killed an eight-year-old border collie on Wednesday afternoon.

Toronto Police Const. Wendy Drummond said a call came in at 1:03 p.m. that a pit bull had attacked another dog on Leggett Avenue, which is south of Lawrence Avenue near Royal York Road.

The killed dog, Lucy, belonged to Noemi Stefenatti, who was going for her daily walk with her granddaughter when she said her dog was attacked by the pit bull.

The attacking dog was not on a leash and was not with an owner.

“She grabbed Lucy and Lucy was bleeding,” said a distraught Stefenatti. “But I was pulling them both. Go away, go away."

Stefenatti said the pit bull grabbed her border collie by the neck and pulled it along a forested pathway, near Chapman Valley Park.

“There was no way to stop him because he was so mad, so aggressive, so mad,” Stefenatti said. “I never saw an animal like that."

Bystander Stefan Luczkiw ran over when he heard Stefenatti screaming.

“The lady was really upset,” Luczkiw said. “She says she lets her granddaughter go here by herself sometimes so, who knows, that could have been her."

Eventually, the pit bull let go, but it was too late for Lucy, who died of her injuries.

The pit bull escaped into the woods.

Though it didn’t have a leash on, the pit bull was wearing a red collar.

Police officers used ATVs to search the area for the dog, but did not immediately find it.

Drummond said they were concerned that the pit bull may attack other animals.

With files from CTV Toronto’s Ashley Rowe