It was a powerful day in Sydney, N.S. as employees at several businesses donned their finest superhero attire for the fourth annual “Caleb’s Superhero Day” in honour of a special little boy.

In March 2015, Caleb MacArthur died from cancer a month shy of his fourth birthday. The beloved little boy was known to dress up as his favourite superhero, Superman, while he underwent treatment at Cape Breton Regional Hospital.

Following his death, his family and the hospital created the charity “Caleb’s Courage” to raise money for pediatric palliative care.

In just four years, the movement has raised more than $400,000 for children in need of critical care.

On Monday, workers at several businesses in Sydney dressed up in superhero garb in honour of Caleb.

“Their story has just broken my heart,” Melanie Sampson, who dressed up as Wonder Woman at the town’s Mazda dealership, told CTV Atlantic on Monday. “I can’t even picture – I have three children of my own – what it must have been like for them.”

Sampson wasn’t the only community member taking part, either.

At the Credit Union bank in downtown Sydney, staff showed off their various superhero T-shirts.

“It’s a very special day in the community help supporting little kids who are fighting big battles,” employee Mark Carabin said. “We just thought, ‘Let’s dress up like superheroes and do our little part.’”

Not too far away, staff at The Cape Breton Regional Hospital Foundation, which helps run Caleb’s Courage, sold pins and T-shirts with the little boy’s image on them.

“I would venture a guess to say there are over a thousand people who are participating in this in different ways,” Communications Officer Mark Inglis said. “We know for certain that we had an order of over 500 T-shirts come in last week. We are down to a bare minimum, just a few of those T-shirts left.”

Inglis said the community’s participation in “Caleb’s Superhero Day” has meant a lot to Caleb’s family.

“It means the world to them to know that Caleb’s legacy is living on forever,” he said. “They have actually created an endowment fund, which means that money is going to be used forever, for the rest of time, to help other little superheroes fighting big battles.”

On Tuesday, students at local Sydney schools will have their opportunity to dress up when it’s local superhero day for them.