It took about 12 seconds to bring down an 11-story dormitory that was built nearly 40 years ago at Appalachian State University in Boone, N.C. Contract Drilling and Blasting LLC used a series of blasts to cause Winkler Hall to implode over the weekend, WSOC reported. The university, which live streamed the implosion, may use the site for a new residence hall in the future.