Nine tenants are homeless after fire inspectors deemed their Fredericton apartment building unsafe.

A blue tarp is stretched across most of the roof, the brick work is crumbling, there are areas where the wood is rotting and fire crews told CBC News no one will be allowed to return until major repair work is completed.

City fire inspector Cameron Dunn said the big concern is water seeping into the electrical system.

"If water is in the electrical system there's potential for a short or something happening that could cause a fire incident," he said.

Dunn said it's unusual to close an entire building.

"It's pretty rare. We may have to close part of a building and maybe move one person to another apartment or get them to stay with friends for a day or two, but this has become a larger incident because of the amount of water in the building at the time."

The nine tenants, some on social assistance, are getting help from the Red Cross and the provincial government. Some are staying in local motels until the situation is remedied.

City councillor Mike O'Brien said he thinks the unsafe building is just one of many in Fredericton.

"We do call it the tip of the iceberg because there is the visible homeless in the city, about 300 or 400, and then below that are people living in situations like this," he said.

The city has ordered the landlord, Bill Petley, to repair the building.

Petley said he plans to complete the repairs as soon as possible, but he couldn't say when residents can move back in.

He said he will be meeting safety and health inspectors next week.