As the massive crane toppled to the ground in lower Manhattan on Friday morning, its huge lifting hook was sent swinging through the air — and into a New York Law School office — as if it were a wrecking ball.

The 4,600-pound apparatus — a huge, red steel orb with a hook at its end that is also known as a “headache ball” — could have caused all manner of destruction, but by luck no one was inside the part-time administrative room on the fifth floor.

“Yes, our building was ­affected by the crane collapse,” said officials from New York Law School. “It is not a wrecking ball, it’s the hook apparatus at the end of the crane.”