LEWISTON – Dan Costello called it a well choreographed dance.

In one of the more nerve-wracking parts of the demolition of three downtown buildings, gutted by arson just days before Christmas, crews slowly, steadily plucked the roof trusses from the wreck of the old Kora building on Lisbon Street.

“The biggest challenge we’ve had to deal with was the impaired condition of the old buildings, particularly the wall between the Kora building and the New England furniture building,” said Costello, owner of Middleboro, Mass.-based Costello Dismantling Company Inc.

The buildings shared a common wall that had signs of wear and stress on both sides. The roof trusses for the Kora building extended into the common wall. A single mistake could have made the common wall crumble, leading to a collapse of the New England Furniture building itself, he said.

“We went in very carefully and systematically took down the trusses,” he said. An 85-plus-foot boom carefully lifted each truss and pulled it free of the common wall.

“And so, truss-by-truss, day-by-day, we took the load off,” he said.

The Kora, Cressey and Greely buildings had disappeared from view by Tuesday morning, replaced by piles of wood and brick.

It’s slow, exacting work when it’s done correctly, Costello said. Building demolition is not a profession associated with having a delicate touch, but that’s just what it requires. Costello is one of a handful of companies that have an excavator big enough to tear down multiple-floor buildings safely. Theirs is a Volvo 460 ultra-high boom excavator topped with a rotating grapple. They have a second, a Komatsu 450, currently knocking down some walls at an Exxon Mobile complex in Brooklyn, New York

His crews use the boom to grip chunks wall and floor, wrenching them free and dismantling the building piece by piece. The result is quite different from what spectators may expect, like the crash of a wrecking ball.

“But there are a million reasons why you wouldn’t use a wrecking ball,” he said. Neighboring properties, for example.

“When you have a building as impaired as these three were, a ball would just devastate them and send them into an uncontrolled collapse,” he said.

Costello said he’s quite familiar with Lewiston. His firm knocked down the old W.S. Libbey Mill in January 2001, followed by the F.W. Webb building and St. Peter’s School last year. It’s one of the few companies in the northeast able to respond quickly to emergencies like this.

“A lot of people do what we do, and they do it very well,” he said. “But we’ve carved out a particular niche that allows us to respond very quickly,” he said.