Commercial passenger plane narrowly avoids collision with mystery object.This sighting was reported from several media outlets in the Greater Toronto Area (GTA) I did not personally witness this event; I am reporting it as it was reported by the several local media outlets. Following is a report from a large newspaper (The Toronto Star) in the area: The pilots of a Porter Airlines flight inbound to Toronto on Monday morning were forced to put their plane into a sudden dive to avoid a mid-air collision with an unidentified object high over Lake Ontario, causing minor injuries to two flight attendants.Now investigators with the Transportation Safety Board of Canada admit they have a puzzle on their hands to determine exactly what the pilots had to avoid.“Nobody knows at this point. It happened so quick,” said Peter Rowntree, senior regional investigator with the safety board.“We’ve got our work cut out trying to figure out what this unidentified flying object was. What did they encounter?” Rowntree said in an interview.“It definitely wasn’t a bird. It was a fairly large object,” he said, describing it as up to three metres wide.There were initial concerns that the object was an unmanned aerial vehicle (UAV), or drone, highlighting once again worries about their growing prevalence and the risks they pose to aviation.Rowntree said it was too soon to say for sure. But he said the location of the incident — at 2,743 metres (9,000 feet) over the lake near the U.S. border, far from shore — is reason for concern if it was a drone.The Porter Dash 8-400 turboprop was on its initial approach to Toronto’s Billy Bishop Toronto City Airport from Ottawa when the two pilots saw they were on a collision course. They had mere seconds to spot the object and react to avoid the danger.“They essentially just pushed the nose down to get underneath it,” Rowntree said.“It’s a big sky out there, so the fact they even saw it is something,” he said, noting that the aircraft was travelling at almost 450 kilometres per hour.Two flight attendants suffered minor injuries in the evasive manoeuvre. They were taken to hospital and released. None of the 54 passengers on board the flight were injured, airline spokesperson Brad Cicero said.At first the pilots believed the object was a balloon, but later thought it could have been a drone, Cicero said.The Toronto Star published the above article. I removed information about this being a possible drone and the concerns about people flying drones that wasn't important regarding the sighting description. The drone they speak of is not a military drone; as Canada doesn't appear to have such craft. A personal drone (UAV) doesn't usually offer enough range to have been at the altitude - and distance from shore - this object was seen. Most commercial UAV drones have a range of between 100 metres and 2000 metres.