Leo McCarthy gives college scholarships to teenagers who pledge not to drink while they're underage. In 2007, McCarthy lost his 14-year-old daughter, Mariah, when an underage drunken driver hit her and two of her friends as they walked down a sidewalk near her home in Butte, Montana. Through McCarthy's nonprofit, Mariah's Challenge, more than 140 teenagers … Continue reading CNN Heroes Top 10: Leo McCarthy