Thousands of people joined local residents and emergency responders from across the nation Thursday to honour two volunteer firefighters who died fighting a blaze last week in Listowel, Ont.

Ray Walter, 30, and Ken Rea, 56, died while fighting a building fire in the southern Ontario town on March 17. The two volunteer firefighters were inside a burning dollar store searching for trapped shoppers when part of the structure caved in.

The deaths prompted an outpouring of grief and support from fire crews across Ontario and Canada, and as far away as Connecticut and Arizona.

Premier Dalton McGuinty attended the service at the Listowel Memorial Arena, while thousands flocked to the town, about 200 kilometres west of Toronto.

McGuinty told the packed crowd that the two men are "nothing less than heroes." He added that when duty called, the men stepped forward and said "Here I am, send me."

Listowel, with a population of 6,000, organized a black ribbon campaign in honour of the firefighters. Black markers hung from road signs, directing visitors toward the arena.

McGuinty added that the families who lost their loved ones should remember that the men didn't die in vain.

"Let the memory of Ken and Ray and their courage give you the courage to carry on. And I'm just here to let you know, right now, 13 million Ontarians are carrying you on their shoulders and in their hearts."

Rea, a 37-year veteran with the North Perth Fire Department, was married and leaves behind three daughters.

Rea's daughters gave their father an emotional goodbye during the service, remembering a man who was "the greatest man" they will ever know.

"You died doing what you loved to do -- protecting your family and your community," the sisters said.

Walter, meanwhile, was married last year and had joined the department only three years ago.

Derrick Frook, a cousin of Walter's by marriage, said that the young man had followed his father's footsteps by becoming a volunteer firefighter. He added that Walter was devoted to his community and his wife.

There was also a moment of silence at the Ontario legislature earlier this week to honour the men.

"They were out doing their job and volunteering for their community to save lives, and in the process of that they lost their own," Oxford MPP Ernie Hardeman told CTV Toronto.

"When this happens to one fireman it affects every fireman in the province."

Officials are still investigating what caused the fatal blaze and the deaths of the two volunteers. Ontario Provincial Police have asked anyone who was in the store before the fire started to contact them.

With files from CTV Toronto's Austin Delaney and The Canadian Press