This is an archived article that was published on sltrib.com in 2007, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

A series of explosions in quick sequence shattered Saturday's still morning air in downtown Salt Lake City, and seconds later what once was Utah's tallest bank tower fell in on itself in a billowing cloud of dust and was reduced to a pile of rubble.

The implosion of the former Key Bank tower - which once stood next to the Crossroads Plaza mall - has been in the works for months to make way for the City Creek Center project. The deed was done in a matter of seconds at 6:40 a.m. - five minutes early to beat an advancing storm.

As the tower dropped, a smile spread across the face of Dave Kasteler, superintendent of City Creek Center contractor Okland Construction.

"There you go, boys," he said. "I'm just glad it came down. Now I'm nervous about the cleanup."

A Baltimore-based demolition company - the same one that brought down the Hotel Newhouse in Salt Lake City about a quarter century ago - had strategically planted 180 pounds of explosive in the basement, second and 10th floors to topple the 20-story structure.

The charges were timed sequentially so that the building would fall away from Main Street yet mostly land within its footprint.

Crews from Controlled Demolition International had notched support beams beforehand to weaken them. The explosives then "cut through the steel beams like a knife through butter," according to company engineer Doug Loizeaux.

Police cordoned off nine downtown blocks, called the dust-impact zone, to keep spectators away from the implosion and the resulting cloud.

The area between North Temple and 200 South and from State Street to 200 West is expected to open Saturday about 10:30 a.m.

Nonetheless, crowds gathered around the perimeter to see the spectacle. About 200 people converged at 200 West and South Temple.

Michael Wilkinson snapped a photo of his wife, Andria, standing on 200 West with the doomed building behind her.

"We had to get a before and after," Andria Wilkinson said.

The Sugar House couple ventured downtown early Saturday morning "to feel the rumble under our feet. You can't feel that on the television," she said.

Her husband added, "We're here for the special effects."

Jeremy and Kristi Renner traveled from Park City to watch the show with their children Chase, 11, and Maggie, 9, and two friends, Rob Taylor and Olivia Andreini, 9.

"It's a once-in-a-lifetime experience," Jeremy Renner said.

A troupe of Brigham Young University students, prepared with safety goggles and blue surgical masks, trekked to the site.

Paris Wilson, 20, Candice Funk, 20, Joel Dayton, 22, and Ryan Lund, 23, made colorful signs to hold up during the explosion.

Lund brandished one that read, "Kaboom!"

"Like Wile E. Coyote. We just picture him pushing the plunger and the building going down," he explained. "That's the only place I've seen it happen - [cartoons] and 'Die Hard'."

After the implosion, the crowds scurried back to their cars as the dust spread out and enveloped the surrounding blocks.

It was "incredible" and "worth it," said Troy Olson, who lives downtown. "It's like a 100-year storm, you know. I wanted to taste some of the dust. That's part of it."

To suppress that dust, crews started watering down the rubble and sweeping sidewalks and streets to ready the area for pedestrians, automobiles, as well as TRAX and bus services.

The dust settled within 15 minutes of the initial blasts.

Guests at the Marriott downtown and the Plaza Hotel at Temple Square were not being permitted to leave those buildings until officials give the all clear. That is expected about 8:30 a.m.

Crews removed asbestos from the tower before Saturday's implosion. But health officials warned that other particulates in the dust cloud could be hazardous and advised residents to stay away for at least four hours after the implosion.

The tower opened in August 1980 to great fanfare as the headquarters of Commercial Security Bank. Commercial Security merged with Key Bank in January 1987, and the building was renamed.

The implosion marks the last - and most spectacular - of the demolition in that block where the $1 billion-plus City Creek Center will open in 2011.

City Creek, LDS Church's mixed-use project blending stores, restaurants, offices and housing, also will stretch onto the ZCMI Center block to the east. Demolition work continues there.

Mike Rios of Salt Lake City remembers watching the Hotel Newhouse tumble down nearly 25 years ago.

On Saturday, he and his wife, Courtney, came downtown with their four kids, Anthony, 10, Aurelia, 9, Rosemary, 7, and Rachael, 5.

"I'm trying to explain [to my kids] about change," Mike Rios said. The city has transformed since he was a child.

And "when they get to my age the city won't look like it does today."

Added Rosemary: "It will be like the first building I saw fall down."

The family shrieked and cheered as the explosives boomed and the former Key Bank tower fell away from the skyline, ushering in clouds of brown smoke.

"That was louder than fireworks," Anthony exclaimed. "I thought it was thunder."