three times of a chance behind you a child having ashma than here? our undercover cameras take you inside the battle. how it can be won. >> the mold is back. it's everywhere. >> and why we're losing. everybody has a breaking point. i'm lester holt and this is "dateline." >>> tonight, breathless. >> my mommy says when i cough, i need my asthma pump. >> imagine living a life tied to a machine. imagine struggling for air as you play, walk or even sleep. imagine fearing that your next breath be your last. welcome to the world of six-year-old amanda santos. >> i can't breathe. i can't breath. >> okay. all right. >> amanda is one of 7 million children in the u.s. who suffer from asthma, but there is something different about her disease. she and hundreds of others like her are more likely to develop, more likely to be hospitalized for, more likely to die of asthma than other children. ♪ i can't breathe ♪ i can't breathe >> nearly a year and a half ago as part of the nbc news in plain sight initiative that reports on poverty in america and supported by the

three times of a chance behind you a child having ashma than here? inside the battle. how it can be won. >> the mold is back. it's everywhere. >> and why we're losing. everybody has a breaking point. i'm lester holt and this is "dateline." >>> tonight, breathless. >> my mommy says when i cough, i need my asthma pump. >> imagine living a life tied to a machine. imagine struggling for air as you play, walk or even sleep. imagine fearing that you