A 62-year-old live-in nanny was seriously injured when the illegal elevator in her Manhattan building broke Wednesday, sending her plummeting more than four floors, police sources said.

The woman was inside the Sutton Place elevator car at about the fourth floor when it suddenly plunged around 4:15 p.m.

The lift crashed down to the basement with such force that it fractured the woman’s spine and several other bones, police sources said.

She was taken to New York Presbyterian Hospital with serious but non-life threatening injuries, sources said.

A Buildings Department source said the elevator was illegally installed in the 1940s and never registered with the department.

After the incident, buildings officials ordered that no one use the elevator. It must first be registered with the department, repaired as needed and registered for annual inspections, according to the source.

A man who lives in the building, according to records, said “no comment” before hanging up on a Post reporter.

No one was home when a reporter visited on Thursday. Two elevator repair workers came to the building in the afternoon–and left when no one could let them in. They said they had never worked on that elevator before.

A dog walker stopped by as well, looking to walk the residents’ Golden Retriever — but also left when no one answered the door, or his calls and texts.