BETHEL — The 120-foot tower of ice constructed by the Bethel Chamber of Commerce blew down in winds that reached nearly 80 mph over the weekend.

Chamber Executive Director Robin Zinchuk said the tower toppled within the perimeter fence just after dusk Saturday in high winds. The underlying metal support structure was bent into three pieces as chunks of ice crashed to the ground.

“The structure swayed under the huge wind gusts during the day,” designer and civil engineer Jim Sysco said. “Weak sections in the midsection of the tower caused by melting in the unusually warm temperatures and bright sun last week caused the upper section to dislodge from the lower section. The pulling on the guy wires, along with the force of the ice coming down, bent the metal like butter and pulled one of the 1,800 concrete blocks that secured the guy wires right up out of the ground.”

Designers had been struggling with weather changes, including a 50-degree thaw last month, and with efforts to get the tower built up to the planned 140-foot height.

The original plan had been to debut the tower at Bethel’s WinterFest 2011 in late January, but the winter’s changing weather pattern delayed that debut.

Ice climbers did a test climb on the tower Thursday in preparation for this week’s climbing demonstrations Tuesday and Friday, which are cancelled.

The tower, which was graced with strings of red and white lights, was built using seven 1-inch pipes bound together, each 20 feet taller than the next and each able to draw up to 90 pounds-per-square-inch of water to the top. The water supply was first connected to the 20-foot pipe; as it dripped out of the top of the pipe, it froze on the way down, coating the structure with ice and creating a foundation.

When the tower reached 20 feet, the water was diverted to the next taller pipe, the 40-footer, then to the 60-foot pipe, then the 80-footer and then the 100-footer. Sysco was pretty confident that, with the water pressure used, the tower could eventually reach 200 feet, but organizers were not planning to go beyond the Federal Aviation Administration mandatory light-height of 150 feet.

Consistent freezing temperatures were a concern right from the start of construction, according to Sysco, who said designers needed a prolonged period of cold weather to create a solid tower.

The chamber had planned to use an estimated 100,000 cubic feet of water for the project, at a cost of $2,000 to cover treatment and electricity costs to pump the water from the Bethel Water District’s reservoir.

According to Zinchuk, the metal structure, guy wires and lights are now all frozen into the pile of ice and “it would be impossible to totally clean the site up.”

She estimates the pile of ice would remain at the site for at least another month, depending on the weather, and the chamber will arrange to clean up the debris as soon as possible.

“We are very grateful that three ice climbers had the opportunity to scale the tower on Thursday before it came down, and we certainly are disappointed that we need to cancel the ice-climbing demonstrations this week. The fact that no one was hurt and there was minimal damage to the fence during the collapse is a blessing,” Zinchuk said.

According to one witness, the tower collapsed into a pile of chips and blocks at Bethel Station. Another witness described the tower as a “stump” Monday morning.

No one at the nearby Casablanca Theater or the Mallard Mart on Route 2 heard the tower crash Saturday. A clerk at the convenience store, who said employees could see the tower from the back door, said the crash was “silent.”

The ice tower was the fourth gigantic winter project created by the chamber and local merchants since 1999, when the 113-foot Angus, King of the Mountain, stood at Bethel Station. In 2008, the chamber organized the construction of the 122-foot Olympia Snowe-Woman at the site, and had hoped to dwarf her height with the recent tower of ice. Last year, the chamber and volunteers constructed the Snow Maze, which was also a struggle during fluctuating temperatures.