PEABODY — Demolition work has begun at the landmark Sears department store at the Northshore Mall.

Sears closed the store in September, one of a wave of store closings around the country. The company filed for bankruptcy protection in October.

The site is slated to become a Life Time fitness center, with a three-story building with an expansive outdoor pool area, featuring a large pool for lap swimming, two smaller leisure pools, a whirlpool and a bistro. It is scheduled to open in 2020.

Sears was one of the original tenants when what was then the North Shore Shopping Center opened in 1958, and it expanded some years later.