Fire officials suspect a Halloween prank may have cost the historic town of Lunenburg, Nova Scotia one of its best-loved buildings.

Built in 1754, St. John's Anglican Church was the second-oldest Anglican church in Canada.

On Halloween, a fire gutted the structure, leaving a blackened shell. People in Lunenburg gathered to watch in shock as their place of worship burned.

"The people of the congregation have come out shocked, hurt, crying," said Rev. Irving Letto.

Lunenburg is one of the oldest towns in Nova Scotia. It's well known for fishing, shipbuilding and as the birthplace of the Bluenose II.

In 1995, the United Nations recognized Lunenburg as a world historic site, one of only 13 in Canada.

Irving Letto

Generations of people have come to the church for weddings, baptisms, funerals, music recitals and gatherings to mourn those lost at sea.

"My life belonged to the church and it's all basically gone in a few hours," said bell ringer Peter Allen as he watched firefighters battle the flames.

Fire officials are investigating, but police believe someone set the fire. The fire spread quickly to engulf the white clapboard building, which sits atop a hill.

"It appears to have been deliberately ignited from the outside and is currently being treated as a crime scene by the RCMP," said Fire Chief Terry Conrad.

"We will exhaust all avenues to identify those individuals responsible," said RCMP Corporal Mark Furey.

He added groups of teens and people in their early 20s were seen roaming through town Halloween night.

The damage has been estimated at between $5 million and $6 million.