From left, Butler High School students Alex Bauer, Madison Kerr, Shannon Gallagher, and Tom Mitch show a replica building they created for the annual Chain Reaction Contraption Contest at the Carnegie Science Center. The students placed in top eight out of 38 teams. The group, led by physics teacher Tad Campagna, won the "People's Choice Award" and the "Best Execution of Theme" award Dec. 4. The team's theme was Harry Potter and the contraption was titled, "For Sirius."