Every explosive demolition has it's own challenges. Tight, crowded spaces and hard, powerful steel are just some of the problems blasters face. In Nigeria, the Bank of Industry building, half-destroyed several years ago by lightning, looms over the city of Lagos. It’s up to blasters Bob Daphne and Mike Perkin of the South African company Wreckers to bring it down safely. In Charlotte, North Carolina, blaster Jim Redyke has a different kind of headache. He’s blasting the Charlotte Coliseum, an irregularly-shaped sports stadium with a very special type of roof.