Cambodia stampede, TSA security, Champions of Change
Cambodian Prime Minister Hun Sen says 339 people have been killed in a stampede during a water festival in Phnom Penh. Tonight, the author of "Extreme Danger: The Science of Your Mind in Danger" explains the panic behind stampedes.
No shoes, no liquids, and now a looming protest over body scans and pat downs. Have we lost faith in airport security? Tonight, meet an American pilot who has launched an online campaign to raise awareness of what he considers to be a violation of constitutional rights.
Related: Do you think airport security is too invasive?
Meet the finalists for Champions of Change. Six-time Olympic medal winner Clara Hughes joins us tonight to introduce two of Canada's top volunteers in the field of health and wellness.
More: Follow Champions of Change on Facebook and Twitter.
Plus Reshmi has the top news stories of the day, and Mark's big question mark in the end of show Disconnect. Tune in tonight at 8:00 p.m. ET live.