We have a policy on event classification that was developed by my colleagues from the Transportation Safety Board of Canada and myself. It assists us in determining the scope of our investigations into each specific event.
There are a number of criteria. I will not go through all of them, but the main one is whether there are lessons to be learned in terms of safety.
Keep in mind that, year in, year out, between 3,500 and 4,000 events are reported to us for every mode of transportation. However, we cannot investigate every one of these events. We have to choose which ones to investigate further, and one of the main criteria is whether there are lessons to be learned in terms of safety to improve Canada's transportation system.