The Spill at Dan River | Disrupting Cancer | The City of Music

Lesley Stahl reports on how the nation's biggest energy company is handling 100 million tons of coal ash waste in North Carolina; Sanjay Gupta profiles billionaire surgeon Patrick Soon-Shiong who discusses unconventional ways of treating cancer; Bill Whitaker travels to Cremona, Italy, to visit artisans who are crafting violins the way Antonio Stradivari did 300 years ago.