live interview today, tuesday, august 3rd, 2010. captions paid for by nbc-universal television and welcome to today on this tuesday morning. i m meredith vieira. and i m matt lauer. it s impossible to know how to describe this tragic story in shreveport, louisiana. six teenagers between the ages of 13 and 18. they re dead. they drowned in what the city s fire chief described as the worst accident he has ever seen. so sad. the group was walking in shallow waters near the edge when one of the boys stepped off a ledge that fell off sharply. one by one the rest of the group went in to help, none could swim. the first teen to fall in was the only one who was pulled out alive. it s a heartbreaking chain of events. the latest in a live report straight ahead on a very, very different note, are you taking some sort of health supplement this morning? more than half of adults in this country do that and most of the supplements are good for you. this morning we ll give you a lis