Nick Dietz compiles some of the latest and greatest viral videos, including Wyatt Scott’s crazy way of announcing his run for Canadian Parliament and a tortoise that can open the door and let himself in. To see these videos in their entirety, click HERE. Source

Preparations for the fourth annual Internet Cat Video Festival are underway in St. Paul, Minnesota. A curator for the event, Will Braden, spoke to CBSN about the convention. Source

Recent surgery to remove a mass on his liver has revealed that former President Jimmy Carter has cancer that has spread. CBS News chief medical correspondent Dr. Jon LaPook discusses the diagnosis. Source

With the FBI reviewing the security of her email system, Hillary Clinton agreed to turn over her personal email server to the Justice Department. CBS News correspondent Jan Crawford reports. Source

Chinese officials say a warehouse filled with explosives is the source of a blast that rocked the industrial town of Tianjin. CBS News correspondent Seth Doane reports. Source

Former president Jimmy Carter, 90, says recent surgery to remove a mass from his liver revealed cancer that has spread to other parts of his body. He says he will undergo treatment at a hospital in Atlanta. Presidential historian Doug Wead spoke to CBSN about the news. Source

Two massive explosions in the port city of Tianjin, China, have killed at least 7 and injured hundreds. CBS News deputy foreign editor Tony Cavin discusses the details coming in. Source

A new study finds walking or biking just 20 minutes a day is enough to help men ward off the risk of heart failure. Chris Martinez reports. Source

A German study claims that parenting can have significant negative impact on your happiness. Some believe it feels worse than divorce, unemployment or the death of a partner. Helen Fisher, a biological anthropologist and senior research fellow at the Kinsey Institute, joins “CBS This Morning” to discuss the findings. Source

There’s proof that it’s never too late to push yourself in the gym. A recent study shows people 55 years and older are the fastest-growing group joining health clubs. Norah O’Donnell met Constance Tillet, a remarkable woman who’s re-shaping more than her body. Source