Four years ago, a huge fireball appeared over the small Quebec town of Lac Megantic. The fireball was from an explosion caused by a runaway train that crashed into the downtown. Nearly 50 people were killed.
That tragedy is being examined again this week in a courthouse in Sherbrooke, Quebec, where three railway employees are on trial for criminal negligence.
We get an update on the trial from Alison Brunette, a reporter for CBC Quebec, based in the Eastern Townships.
Click listen to hear more.