America's largest public transit project was called off Thursday and the reasons for the cancellation are giving Ottawa's LRT critics more ammo.

The Trans Hudson Mass Transit Tunnel would have doubled rail capacity between New York and New Jersey.

The project was derailed after costs skyrocketed.

An estimate started off at $5 billion, now holds a price tag of $8.7 billion, and is estimated to rise to $14 billion.

New Jersey's governor called the whole thing off saying he could not allow taxpayers to foot the ballooning bill.

While the numbers in Ottawa are smaller, one mayoral candidate predicts a similar story. Clive Doucet is for light rail but against the downtown tunnel.

"Typically tunnels run, on average, 60 per cent over," says Doucet. "So, say it's budgeted $2.1 billion … you're looking at $3 billion."

Ottawa's proposed underground tunnel is 10 stories underground, 3.2 kilometres, and $735 million. The total cost for the project including the tunnel is $2.1 billon.

"From day one I've expressed concerns that I don't want this project to get out of hand," says mayoral candidate Jim Watson.

Watson says due diligence will keep taxpayers off the hook for any cost overruns. He says he would have a private sector board of management oversee construction to avoid the problem.

Ottawa mayor Larry O'Brien says he is confident the project will come in under budget, and Ottawa taxpayers have nothing to worry about.

"We're going to make sure we have a fixed price contract to move ahead."

With a report from CTV's Karen Soloman