LAWRENCE, Mass. -- Police in a Massachusetts town are beginning to unravel the story of a mysterious safe found in a parking lot stuffed with almost $180,000.

Firefighters out on a routine patrol Friday discovered the 2,000-pound safe, which had been discarded in a lot frequently used as a trash dump in Lawrence, and reported it to police, reported WCVB-TV in Boston.

The safe was transported to police headquarters, where officers labored to break through the back wall of the metal container.

Inside, they discovered thousands of dollars in cash dating, at the latest, to 1982, according to Det. Thomas Cuddy.

Cuddy said that the department is following up on several leads related to robberies in the area during that time but declined to elaborate.

He said police have been canvassing the neighborhood for evidence, and they believe the safe was deposited in the lot about three weeks ago.

Cuddy said the person who abandoned the safe may not have known about its contents, but because of the container's size and weight, it is possible that the money was deliberately abandoned in the lot.