It has been almost 4 years since the U.K. public voted to leave the European Union. Today it actually happens. Source

The impeachment trial of President Trump could end soon if senators decide not to hear from new witnesses.CBS News chief congressional correspondent Nancy Cordes and White House correspondent Paula Reid joined CBSN to discuss what comes next. Source

With just three days until the Iowa caucus, the 2020 Democrats not participating in the impeachment trial of President Trump scramble for public attention. Ed O’Keefe reports on the presidential hopefuls’ final push before voting officially begins Monday. Source

The U.S. now has six confirmed coronavirus cases, one recently found to be a case of person-to-person transmission. The State Department issued a critical warning to not travel to China. David Begnaud is at a California hospital where doctors are ready to treat people evacuated from China this week. Source

Advertisers such as Facebook and Hyundai are releasing teasers early to spark interest. Plus: Trump vs. Bloomberg. Source

The most recent case in the U.S. is a man who hadn’t visited China, but contracted the virus from his wife, a worrying development as the disease spreads. Source

With child care costs averaging at about $10,000 per year, many Iowans struggle to make ends meet. CBS News takes a look at how this affects caucus voters in Every State Has a Story. Source

Social media company has drawn fire for allowing hoaxes and misleading posts about the outbreak to go unchecked. Source

President Trump held a rally in Iowa to fight for spotlight as Democratic candidates focus on the state. CBSN political reporter Caitlin Huey-Burns joined CBSN from Des Moines and shared what voters are feeling ahead of the caucuses on Monday. Source

In this week’s “48 Hours,” a Michigan woman was convicted of murder and arson after authorities say she set her home on fire to kill her husband and then ran him over with a van when he escaped the flames. She was sentenced to life in prison but convinced a judge that she didn’t get a fair trial and was released. “48 Hours” correspondent Erin Moriarty joined “CBSN AM” with more. Source