The sound of fire alarms and sirens signal danger for most people.

For 4-year-old Brandon, however, the noise is the sound of a dream come true.

Brandon, whose last name has been withheld for privacy, has spent his entire young life in and out of doctors' offices and hospitals after being born without working kidneys. In treating his end stage renal failure, Brandon, of Palmdale, Calif., has suffered through painful and grueling daily treatments of dialysis to stay alive.

Earlier this month however, Brandon, whom could be called a living miracle for making it this far, put all that behind him.

Brandon, who wants to be a firefighter when he grows up, saw his dream come true.

ABC News' Abbie Boudreau joined Brandon and his family as Brandon became a firefighter for the day with Los Angeles County firefighters.

The day began with a fire truck ride and then saw Brandon up in the air on a helicopter tour of the fire district.

"He's been through a lot and the fact that he's here with us is awesome," Brandon's mom told Boudreau between tears.

Also along for the ride was a family member who will play an important role in Brandon's future: his uncle, Ciro Errico, his mother's brother, who will soon be giving one of his own kidneys to his nephew.

"I'm the actual donor and I decided to come forward with it after seeing what he's going through, and my sister," Errico said, also choking back tears.