Over 70 million under weather alerts today as two heat waves hit the US

More than 70 million people are starting the July 4th holiday weekend under heat alerts. A heat wave in the south and Mississippi River Valley is peaking Friday, with temperatures around 100 degrees Fahrenheit. It's a deadly heat that's already killed at least 13 people this month. Some relief should be coming this weekend, into next week. But out west, another heat wave is just beginning.