YouTube – Wildly successful but often lit up by controversy, the video-sharing site has its pros and cons. Lesley Stahl talks to its CEO, Susan Wojcicki, about its policies.

Unsheltered – Seattle, Washington is one of the fastest-growing cities in America and one where the homeless crisis is among the most visible. Anderson Cooper goes there to report on how one city is dealing with what has become a national problem.

Built by Angels – Ethiopian pilgrims have been trekking to this mysterious holy site for centuries to visit its rock-hewn churches carved out of the African plateau. Scott Pelley made the trip in time for the Ethiopian Orthodox Christmas vigil and tells this remarkable story.

A Central Ally – In the last year, 90,000 Salvadorans have been apprehended at the U.S. Southern border. The migrants are fleeing economic hardship and, in many cases, gang violence – a vicious combination making it extremely difficult for Nayib Bukele, El Salvador's young president, to improve his country. Sharyn Alfonsi reports.

The Lost Music – An Italian composer and pianist who converted to Judaism, Francesco Lotoro, has made it his mission to recover, catalog, and perform music written during the Holocaust – including works done secretly by prisoners in Nazi concentration camps. Jon Wertheim reports.