Trains careening down mountainsides, unable to stop. Passenger cars separating from a manned train. Freight cars rolling across the Canada-U.S. border.

In the past 13 years, there have been 459 cases of so-called runaway rolling stock, hundreds more than previously thought.

Following the Lac Megantic tragedy — when an insufficiently secured, parked train ran down a hill and exploded, killing 47 people — it was widely reported that there were about a dozen incidents of runaways a year.

But in fact that only counts examples where an uncontrolled train rolling down the track was the main issue, not when it led to larger problems like derailments and collisions, such as in Lac Megantic.