Firefighters are appealing for funds to rebuild a memorial for Ontario firefighters killed in the line of duty, one destroyed by a shocking act of vandalism in May.

"This shameful act was an insult to the memories of 483 firefighters and an insult to all living firefighters in Ontario," Fred LeBlanc, president of the  Ontario Professional Fire Fighters Association, said Friday at Queen's Park as he launched the fundraising campaign to raise $500,000.

"We are going to rebuild these walls, probably in a different style of granite should, very unfortunately, any future vandalism occur at this site," he said.

Community Safety and Correctional Services Minister Rick Bartolucci called the crime "cowardly," saying the act of vandalism struck at the heart of the deep respect society has for firefighters.

On May 12, a vandal desecrated the memorial with anti-government graffiti. A black glob of paint covered the names of fallen firefighters. Other sections of the tribute had messages that said "Firefighters 4 McGuinty," "Guns bad" and "Dalton gang."

Chemicals used to remove the paint caused even more damage. Even so, some paint stains are still visible.

At the time, there was speculation the monument was vandalized because Premier Dalton McGuinty promised firefighters extra health and disability benefits during the last election.

LeBlanc called on all fire service workers and the public to contribute to the fund.

As part of the campaign kickoff, the province of Ontario pledged to donate $100,000.

LeBlanc also reminded the public that an $11,000 reward is still available to anyone who provides information leading to the arrest of individual responsible for the vandalism.

"I know that someone out there knows who committed this crime and I'm calling on you to think of the families of the firefighters and do the right thing," LeBlanc said.

Video surveillance footage captured images of a white male suspect with a backpack, but it's grainy and police have been unable to identify the person so far.

Contributions to the fundraising campaign can be made at any TD Canada Trust bank location.

With a report from CTV Toronto's Paul Bliss