Following the aftermath of the condominium collapse in Surfside, Florida, many Illinoisans are wondering could a similar disaster happen here? The 21st spoke to two chief engineers to hear more about building safety. 

Guests: Nigel Boston and Simon Singh.

Public key crypography is a system for maintaining privacy in communications that has allowed the information age to flower. Until recently, the true story of its invention was kept secret by the British government. Today on Focus, we're joined by journalist Simon Singh and expert Nigel Boston to hear the full story.