When an accident happens, the Transportation Safety Board is responsible for investigating to determine the cause. I would say that we, ourselves, are under investigation in some way. The board may find that we did not do our job properly and submit a recommendation.
We still send someone to the site, especially if there are injuries. We must also check whether rules or regulations were not followed. We have the right to investigate to determine whether someone did something that was not in line with the regulations.
But, as for the cause of the accident, it's the TSB that investigates. Its employees go to the site. We have the power to appoint someone we call the minister's observer, someone who will liaise between the investigators and the minister should something need to be resolved right away.