it was part of a series of cocaine busts over the last few weeks. in all 26,000 pounds seized worth an estimated $350 million. tonight there's growing concern about vaping after eighteens were hospitalized for serious lung damage. nbc's joe fryer has that story for us. >> reporter: at children's hospital of wisconsin, eighteen agers have been hospitalized with severe lung damage in just the past month, and doctors suspect vaping is to blame. symptoms, extreme coughing, fatigue, and shortness of breath. >> vaping is causing harm to our kids. and we want that message to be loud and clear. >> reporter: state officials say vaping is the common thread among the eighteens, but they've yet to determine if a specific device or substance was the cause. with an estimated 3.6 million teens and preteens vaping last year, health officials and parents worry it's a trend moving in the wrong direction. this week vaping was front and center in congress for a hearing focused on the popular ecigarette brand juul.