3-2-1, BAM! Georgia Dome imploded in downtown Atlanta

ATLANTA (AP) - One of the nation's largest domed stadiums collapsed Monday into a pile of jagged concrete and a vast cloud of dust in a scheduled implosion in downtown Atlanta.

Nearly 5,000 pounds (2,270 kilograms) of explosives were used to blast the Georgia Dome in Atlanta to smithereens at 7:30 a.m. Onlookers gathered at skyscrapers' windows, at a restaurant atop the city's tallest hotel, in parking lots and on nearby streets to watch the destruction of the landmark stadium.

The dome opened in 1992, and it was flattened in just about 15 seconds. The Georgia World Congress Center Authority, which includes the 71,250-seat dome, had said it would take 12 seconds for the explosives to go off plus another 3 seconds for sections of grandstands to hit the ground.

The explosives went off in a spiral around the stadium as it collapsed on itself. A vast debris cloud hovered over the site before slowly drifting across downtown.

The dome has been replaced by the $1.6 billion Mercedes-Benz Stadium next door.

A 5-story tall industrial strength curtain between the two stadiums had been erected to protect the new venue from damage, officials said. Only 83 feet (25 meters) - less than 30 yards - separated the two venues. The Georgia World Congress Center, Atlanta's main convention center, is also just feet away.

Protecting both of those structures was "one of the unique challenges" of Monday's blast, said Morgan Smith-Williams, a spokeswoman for the Georgia World Congress Center Authority, which includes the dome as well as the new stadium.

"There was no damage to Mercedes-Benz Stadium or the Georgia World Congress Center," she said Monday morning, after a post-blast briefing from the Detroit-based Adamo Group that's demolishing the dome.

The new stadium is home to the NFL's Atlanta Falcons and Major League Soccer's Atlanta United.

In addition to the retractable roof that opens like a camera lens, Mercedes-Benz Stadium boasts a 1,100-foot (335-meter) "halo board" video display and a giant steel sculpture of a falcon with its 70-foot (21-meter) wingspan at one of the main entrances.

Several streets and parts of Atlanta's transit system were closed to accommodate the blast and spectators.

The idea for the Georgia Dome dated to the mid-1980s, when civic leaders recommended a domed football stadium adjoining the city's largest convention center, the Georgia World Congress Center. It cost $214 million.

The dome was the site of high school football state championships, Peach Bowls, SEC championship games, two Super Bowls, 1996 Olympic basketball, three Final Four NCAA basketball tournaments, concerts, pro wrestling, and other events.

It also hosted gymnastics during the 1996 games, where Kerri Strug famously vaulted with two torn ligaments in her ankle to help the U.S. beat Russia for the gold medal in team gymnastics. Despite the injury, she stuck the landing, then collapsed and was carried off the mat by her coach Bela Karolyi.