Demolition has begun at the Twin Cities Army Ammunition Plant in Arden Hills, the massive suburban parcel that the Minnesota Vikings once seriously considered for a new stadium.

The 430-acre property belongs to Ramsey County, which closed on a $28.5 million purchase deal last month with the federal government and hired a St. Paul contractor to knock down 25 vacant buildings where workers made ammunition during World War II and the Korean and Vietnam wars.

A ceremonial groundbreaking featuring elected leaders will be held June 7.

The county and Arden Hills are working on a master plan to guide redevelopment of the property and eventually plan to solicit proposals from developers for a mix of different projects, county project manager Jerome Biedny said.

The county hired Carl Bolander and Sons last year to clear the site and clean it to housing standards, a project costing $24.5 million. Demolition is expected to be finished by the end of the year.