The top CNN Heroes, chosen by a blue-ribbon panel from an initial pool of 9000 viewer nominations, were each honored with a documentary tribute and introduced by a celebrity presenter. Each of the top 10 Heroes received $25,000.

Loki Films directed documentary tributes for two of the top 10 CNN Heroes: Leo McCarthy and Mary Cortani.

Leo McCarthy lost his 14-year-old daughter, Mariah, when a drunken driver hit her and two of her friends as they walked down a sidewalk near her home. Thus Mariah's Challenge was created, which rewards teens with scholarships if they stay drug and alcohol free for four years.

"Mariah's Challenge stands for integrity, character and honesty and living a life of simple self-respect," said McCarthy.

Mary Cortani, who is a veteran herself, started a non-profit called Operation Freedoms Paws that helps veterans train their own service dogs in northern California.

She says that "service dogs are but one tool, but they're a very important tool, in the healing process for our veterans."

To learn more and get involved with CNN Heroes, visit cnn.com