Severe weather risks for millions of holidaytravelers as TSA screens record number of passengers

The TSA screened the highest ever number ofpassengers in a single day on Friday, almost threemillion, while more than 38 million are expected to hitthe roads over the holiday weekend. The record travelcomes as millions are at risk of experiencingdangerous heat, tornadoes and other extreme weather.NBC News' Priscilla Thompson reports.