After 39 years, Knapp and Storms Halls are hosting their final party Tuesday. Aided by approximately 120 pounds of explosives, the towers should take less than a minute to collapse in on themselves at 10 a.m.

Heavy dust from the buildings, which has played host to 42,000 dorm-dwellers since opening in 1966, should settle within five minutes, leaving spectators with their memories and a 40-foot pile of debris.

“We’re prepared for whatever crowd size shows up,” said Dean McCormick, assistant director of construction services for facilities planning and management.

Kerry Dixon-Fox, architect for facilities planning and management, said demolition subcontractor Controlled Demolitions Inc. of Phoenix, Md. said approximately 5,000 spectators typically show up to implosions, although spectators are not encouraged.

“This isn’t an entertainment event,” she said. “It’s not a football game.”

According to ISU News Service, alcohol and overnight camping are prohibited, although spectators will be let on-site at daybreak. Spectators can watch from fields to the east or west of Towers, depending on wind direction.

The Ames Police Department and ISU Police will be on-hand for crowd control.

Dixon-Fox said about 1,000 holes for 60 pounds of various types of explosives have been drilled in each building. Explosives are present on the ground, second, fourth and seventh floors, which are circled with black fabric to prevent flying debris.

Debris from the 129-foot buildings, two of the tallest in Ames, is planned to be used in the parking lot of the new dairy farm facility south of Ames — remaining debris should be recycled and landfilled by contractor Peterson Contractors Inc. of Reinbeck.

Clear skies are predicted Tuesday with winds blowing to the south at 5 mph. Temperatures are expected to be 90 degrees, with a 10 percent chance of rain.

No restrooms will be available at the demolition site.