As you know, railway transportation is mostly under federal jurisdiction. Therefore, even if Quebec wanted to intervene in an accident such as Lac-Mégantic's, it would be unable to do so. It would have happened a long time ago were it possible. For example, the Automobile Insurance Act, which provides for automatic compensation, excludes trains simply because of jurisdictional issues, whereas in other states like Australia—I am choosing Australia as an example because its federal regime is similar to ours—not only are car accidents covered by automatic compensation, but train accidents are as well.
This really is about shared jurisdiction. The Quebec government could in fact go that way for its internal railway tracks over which it has jurisdiction. The problem or advantage is that internal railway tracks, which fall under Quebec's jurisdiction, go through very sparsely inhabited areas, whereas tracks that are under federal jurisdiction go through Quebec's cities and villages. Those tracks present the greatest risk of incidents in which there would be victims suffering bodily harm and victims of property damage.