4 year old autistic boy Greyson breaks his silence thanks to a stranger with a truck...

Meet Frank Diaz, Fresno city garbage man. Everyday he gets into his truck, drives through neighborhoods and picks up trash with pride.

It’s his job, his livelihood and his passion.

“I love the community, everything that we do is for the community, I grew up in Fresno,” says Diaz.

But little did Diaz know that his work carried an incredible impact. His day’s duties became a weekly treat with extraordinary bearing on one family.

Every Wednesday afternoon, four-year-old Greyson Kelly runs down his driveway and waits patiently for Frank Diaz to come by. The roar of his truck sparks excitement.

Greyson can hardly contain himself. It’s his way of communicating, something that often doesn’t come easy.

“You see the way he reacts. He lights up, his entire body feels joy,” said Chrissy Kelly, Greyson’s mother.

Greyson has autism. He doesn’t talk much and his parents struggle to get inside his head. But Frank and his big shiny truck broke into the little boy’s world.

“He heard it and said I want truck, and I was blown away that not only did he hear, and process, but he said three words to me,” said Chrissy. When asked about Frank Diaz, she said, “He shows me that things are going to be okay.”