A St. Paul riverfront smokestack that has stood for more than 90 years will be brought down with explosives Sunday morning as part of the ongoing demolition of the Island Station power plant.

A crew from Idaho-based Advanced Explosives Demolition will detonate explosives placed in the chimney, which rises 290 feet over the Mississippi River near Shepard Road and Randolph Avenue.

The explosion is scheduled for 10 a.m. Police will be on the scene to enforce a 1,000-foot perimeter around the site, and Randolph Avenue will be closed from 7 a.m. to noon between Shepard Road and the High Bridge.

The site of the former coal power plant, which has been vacant for 41 years, was purchased last fall by St. Paul River Walk of Scottsdale, Ariz., for $4.05 million. Developers have not yet said what they plan to do with the property.

The property's former owners, Breckner River Development of Burnsville, had been trying to sell it for years. Last summer they successfully fought efforts to have it locally designated as a historic property. The plant had repeatedly failed to win federal historic status.

The demolition work, supervised by Frattalone Companies of Little Canada, should be finished by late spring, said Robert Humphrey of St. Paul's Safety and Inspections Department.

Advanced Explosives Demolition used explosives three weeks ago to crack the concrete ring beam at the Metrodome, and in 2009 blew up the old Lowry Avenue Bridge in Minneapolis.

KEVIN DUCHSCHERE