If it wasn’t for a dog named Lucy, Florida resident Lisa Potts thinks a man with a knife could have harmed her entire family. Unfortunately, it cost the brave pit bull her life.

“She saved all our lives,” Potts told The News-Press. “She really did.”

On Friday, Potts came home to find her ex-boyfriend, Walter Williams, inside. First, Williams started hitting her, says Potts. Then he grabbed a knife. That’s when Lucy sprang into action.

“Lucy lunged at him and he caught her right in the neck,” Potts told WBBH-TV. “She still was fighting him, and that’s when all three of my sons jumped on Walter and held him down to the ground.”

One of Potts’ sons was hurt in the struggle, but Lucy suffered far more serious injuries, getting stabbed three times.

“Once I got her downstairs I just asked someone for a towel and applied [as] much pressure as I could to it to try to save her life,” said Potts. “I kept just trying to be happy and calling her name and ‘come on, Lucy, come on.'”

Despite Potts’ efforts, however, Lucy went into cardiac arrest on Saturday and died.

“She was a fighter and she did good, she really did,” Potts told WINK News. “If it wasn’t for her, you know, he could’ve probably stabbed all of us.”

Williams is now in jail for battery, but authorities say he may face additional charges.