Entertainment21 & Under: Hottest Breakout Stars

THE GIRL NEXT DOOR

Heroes star Hayden Panettiere has conquered – and saved! – the world on her hit show Heroes, but in real life she proved to be more than just a spokesmodel and red carpet fixture. The sweet-faced blonde, who's only 18, risked her own life as she took a stand in dangerous Japanese waters to attempt to save a school of dolphins from slaughter.

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