Wisconsin: Safety with dynamite. A construction contractor looking at blueprints, workers preparing to blast, workers drilling into side of quarry, workers stuffing explosives into hole, a exec from the quarry sets up a demonstration with metal pins on local woman’s porch to show how little impact the blast has on the surrounding area, men move a portable seismograph to blast site, rock explodes, good shot of it, pins have not moved, sales guy shows seismograph results to neighborhood business people.