A 21-storey building in downtown Richmond, Virginia, was demolished in a spectacular implosion. <br /> <br />The former Dominion Energy office tower came down in just 20 seconds. <br /> <br />The tower, completed in 1978, had been vacant since last autumn when the company relocated its offices to a new building. Report by Avagninag. Like us on Facebook at http://www.facebook.com/itn and follow us on Twitter at http://twitter.com/itn
