On March 9, 1911, DuPont’s Hercules Powder Plant, located on 190 acres on the west side of Pleasant Prairie, exploded. The company was manufacturing gun powder and dynamite. Nearly 280 tons of dynamite and 105,000 kegs of black powder had been housed at the plant. The massive explosions left most homes within five-miles of the blast center uninhabitable. Several hundred people in Pleasant Prairie were injured, and one plant employee, E.S. Thompson, was killed. It was said that the blast formed a crater one hundred feet deep under the former dynamite house. Damages were estimated at $1,500,000. The force of the explosion and shock was felt for over 100 miles. There are very few left who experienced the tragedy, but remnants can still be found today scattered throughout the Des Plaines River Basin area just east of I-94 and south of Highway 50 (on privately owned property).

Recently, one resident who was clearing out brush and overgrown trees approached the Historical Society with his discovery. In his back yard, underneath loads of debris, he found a mysterious, massive stone structure along with blocks of concrete. The structure may have housed an area where lead bullets were made before being filled with gun powder from the plant, and the blocks of concrete may have balanced a water trough coming from the Des Plaines River. The Society is currently conducting more research in the matter. To learn more about the Historical Society, contact Jean Werbie-Harris at [email protected] or (262) 947-3600.