From CBC Ottawa:
OTTAWA - Police have detained a passenger for questioning after authorities shut down the Ottawa International Airport Wednesday morning to investigate a suspicious package.
Airport officials said the package was found at 8:30 a.m. in some checked baggage during screening. They wouldn't say what was in it, just that it warranted a wide-scale evacuation.
Flights were grounded, and some planes were cleared after passengers had already boarded.
Officials escorted between 400 and 500 passengers and staff from the recently opened terminal building.
Planes that had recently landed were being kept away from the building.
After investigation, the all-clear was given at 12:30 p.m., and officials expected to allow passengers and staff back into the new terminal building at 1 p.m.
The airport authority said this is the first total evacuation of the airport.