Cops shot and killed a pit bull after it mauled a smaller dog to death in upper Manhattan on Wednesday.

Jada, a Shih Tzu, was being walked at Hillside Avenue and Sickles Street in Inwood at 7 p.m. when the bigger dog attacked.

Rafael Alvarez, 40, who had been caring for Jada for a friend, suffered a lacerated hand trying to save her.

“It just wouldn’t let her go,” he said. “I couldn’t get it off. She was crying in its jaws.”

Two cops rushed to help, but when they couldn’t stop the attack, one shot the pit bull twice.

“I don’t know what a pit bull is doing walking around here loose off a leash,” said Jada’s tearful owner, Joselyn de la Cruz.

The pit bull’s owner wasn’t charged because he was trying to put a leash on the dog at the time.