A terrifying scene unfolded in a Bensonhurst home Sunday morning, where police say four young sisters were attacked by their uncle —and it was an 11-year-old girl who called 911 and helped save their lives.

It happened around 10:15 a.m. NYPD officials say the 11-year-old girl told a 911 dispatcher that she and her siblings had been stabbed but didn’t know her address. The call center used location technology to trace the phone and direct officers to the home.

When police from the 62nd Precinct arrived, they were let into the home’s first floor by another child who was not injured. Officers heard screaming behind one of the doors and kicked it down.

Inside, officers say they found 49-year-old Longqian Chen holding a blood-covered meat cleaver. Blood was also found on the floors and walls. Officers gave several commands for the man to drop the weapon, but he refused and advanced toward them. Two officers fired seven shots, hitting Chen and stopping the attack. The entire encounter was captured on body camera.

Four girls—ages 8, 11, 13, and 16—were found with serious stab and slash wounds inside the apartment. EMS crews provided medical treatment at the scene before transporting all four to Maimonides Medical Center. They are all expected to survive.

Chen, who was also taken to the hospital in critical condition, is the girls' uncle, according to police. Two knives were recovered inside the home: The meat cleaver and another bloodied knife found in a different room.

Police say the motive is still unclear, but family members told investigators that Chen has a history of mental illness.

Neighbor Humberto Huerta, who has lived on the block for 10 years, said, “I was really shocked, nothing like that ever happens here.”

Police are praising the children for their courage—especially the 11-year-old who, despite her injuries, made the 911 call that may have saved her sisters' lives.