There's what happened on the mountain just about two months ago. A boulder came down. It smashed the rail. It broke the rail, shattered ties, and moved the track over. The train came down, with no patrols.
Because they don't have patrols on that mountain, the crew was bringing the train down more slowly. They came upon this broken rail. Rather than throwing the train into emergency, which means you put all the brakes on, but which can risk causing the rail to shift and lead you to end up going all over the place and derailing, the engineman handled the train and brought it to a stop with dynamic breaking. Because there were two units on it that had dynamic breaking, he was able to bring the train to a stop, but not until they went over the broken rail by 24 cars.
They had to separate the train and rebuild the track, and then the train moved on. Since then CN has put patrols on that mountain again. That was never reported to Transport Canada, because it was only an incident.