Ottawa Police have closed Laurier Avenue in the downtown due to a gas leak investigation.

340 Laurier Avenue West has been evacuated.  The entire 15-storey building has been cleared.

Ottawa Fire officials suspect a leak in a boiler on the roof of the building may be to blame.

There are no injuries.

Earlier this morning, employees in the building noticed a smell of gas in the main lobby.

An Ottawa Fire Department Hazardous Materials team is investigating.

OC Transpo buses have been called in to provide a warm place to stay for the affected workers.

More later.