You're about to meet a brave and quick-thinking young girl. Home alone when a burglar broke in. We're now hearing her 911 calls and from the girl herself. There she is about what she did with that... See More
You're about to meet a brave and quick-thinking young girl. Home alone when a burglar broke in. We're now hearing her 911 calls and from the girl herself. There she is about what she did with that knife that she's holding that helped police catch the thief. Mariana is here with us from fusion. Reporter: You're 12, you're home alone. A robber smashes the the door open. Someone is outside in my backyard. And they're about to break open the door. Please help, please help. Reporter: This morning, a frightening 911 call made by a brave 12-year-old girl witnessing man trying to break into her home. Please hurry up. Please, please, please. How old are you? I'm 12. You're home alone? Yes, please help. Reporter: First alerted to the danger by the family dog. She re-created her survival strategy. I heard Sampson bark. I decided to go over here and look from there. Then I saw a guy there doing something to the door. Reporter: Home alone, but not without protection. She grabbed a large butcher's knife and her phone. I went to the bathroom and locked myself in. Reporter: The intruder smashing in the glass door. She immediately called 911. What do you hear? It's a noise. Like something scratching. Scratching something. Like scratching at the door? Yeah. Reporter: The thief ran off empty handed when the cops showed up. Officers were able to catch him. He opened the door and ran and jumped a few fences. And they caught him. I'm so proud of her. She's a very brave girl. Reporter: A word of advice. Remember to keep a knife with you, that's for sure. Reporter: Wow. That is the advice from that brave little girl. I don't know that every parent would agree. I think keeping butcher knives out of the hands of children might be wise. Maybe a cell phone. Hide. And when they leave, call 911. It's great having Marianna with us. From fusion. A joint venture of ABC news and univision. Check your local listings to see her show, fusion live, which airs nightly. Thank you once again.
This transcript has been automatically generated and may not be 100% accurate.