Key Bank tower implosion video 1

Key Bank tower implosion video 2

Boom ... boom ... boom, then a pause, and finally, an office tower that has been part of the Salt Lake City skyline for almost 30 years met its end early Saturday.

At 6:38 a.m., in the soft early morning light under dark clouds that blanketed much of the sky, the former Key Bank tower, 50 S. Main, came crashing down. Hundreds of employees from Key Bank and other former tenants watched from surrounding office buildings.

Julie Nelson, a 31-year employee of Key Bank, watched from the current Key Bank tower, a block east.

"It's bittersweet," she said later. "It was great to watch, but it's sad to see it go."

Nelson remembers the day in August 1980 when the tower celebrated its grand opening. She was pregnant with her first daughter.

In the minutes leading up to the implosion, the building stood quietly as onlookers watched and waited. Then, without warning, the silence was broken by a sequence of nine blasts that rattled windows and shook the ground. About three seconds later, the tower collapsed in on itself, falling slightly to the southwest, just as demolition planners had hoped.

In the days before the implosion, officials said the chief threat to the implosion plan was weather, as lightning or extreme winds could potentially force a postponement. The implosion came about seven minutes ahead of schedule to prevent lightning flashes looming on the horizon from posing a risk, and a steady but gentle breeze helped the dust dissipate more quickly.

Employees watching from neighboring buildings had been warned they could have been confined inside for as many as four hours, but they were given the "all clear" to leave within a half-hour after the implosion.

The 20-story tower was built in the late 1970s and, until recently, housed the offices of Key Bank as well as several law firms, legal support services and other companies. It fell Saturday to make way for The Church of Jesus Christ of Latter-day Saints' City Creek Center development.

The building left an approximately 40-foot heap of rubble in its former footprint — 36,000 tons of steel, concrete and glass, most of which will be hauled off and recycled.