Senate hearing focuses on how security threats have changed in the 20 years since 9/11

The Senate Homeland Security Committee held a "Worldwide Threats" hearing Tuesday morning as lawmakers try to understand how national security has changed in the 20 years since the 9/11 terror attacks. CBS News Homeland Security and Justice reporter Nicole Sganga spoke with CBSN's Tanya Rivero about the hearing, at which Homeland Security Secretary Alejandro Mayorkas, National Counterterrorism Center Director Christine Abizaid, and FBI Director Christopher Wray testified.