About 20 homes in Hants County were evacuated for about an hour on Wednesday evening after a roof collapse at a local rink forced officials to release ammonia in the arena into the air.

Emergency crews were called to the Newport and District Arena just before 3 p.m. on Wednesday.

Just before 7 p.m., a section of Highway 14 near Brooklyn was closed as several businesses and houses within a one-kilometre radius of the arena were evacuated. Residents were told they could wait at the Brooklyn fire hall.

Emily Hines, one of the evacuees at the fire hall, said she knew shortly after 5 p.m. that she would have to be out of her house.

"I was having a visit with my oldest daughter when a knock came to the door and they told me I had to evacuate by 7 o'clock," she said. "No concerns, it's being well looked after."

By 8 p.m., the evacuation order was lifted and the residents were told they could return to their homes.

Andy McDade, a fire chief with the Brooklyn Fire Department, said there was a worker inside the arena at the time of the collapse, but the person was not injured. The roof caved in and some outside walls buckled.

Brooklyn Fire Department Captain Doug Tynch said the building is destroyed.

Activities cancelled earlier in the day

McDade said the rink is a busy arena that was due to host a number of activities on Wednesday, but staff noticed some problems with a twisted beam earlier in the day and cancelled those events.

A local gas company released the ammonia gas from inside the building, McDade said, adding RCMP and emergency officials went door-to-door warning neighbours to leave their homes on the advice of the gas company.

A Nova Scotia Power cut electricity to the building and a hazardous materials crew was also at the scene.

Rink chair Garnett Davison says he was called Wednesday morning about a twisted beam at the rink. (CBC)

Garnett Davison, who has been chairman of the Newport and District Arena for 12 years, said the rink was built in 1972. It is run by a rink commission and gets support from the municipality.

He said the rink had snow on the roof, but it never looked like too much snow. He said he got the call this morning about a twisted beam, then called an engineer and the insurance company.

'Just a dust cloud'

Davison was outside the building when the roof caved.

"All of a sudden it went down, poof, just like that. There wasn't much noise, just a dust cloud," he said.

Davison said starting over is a daunting task.

"All I could think of is, 'There's our rink gone.' Kind of a devastating thing," he said.

"Still haven't gotten over the shock of it yet or haven't got into shock yet, I'm not sure. The work we'll have to do to rebuild is going to be a major, major rebuild."

Hines said she found out about the roof collapse through Facebook. She remembers when it was built.

"I had been involved years ago when they built the rink because my kids played hockey and we didn't have a rink then and they had to play in Halifax and Windsor and then we got the rink out here," she said.

She said she's confident the community will rebuild.