I would echo what Beisan said. I would add that I think the best prevention possible is training, as long as it's mandatory for all employees and employers. I believe Monsieur Parent said that he was able to get three hours of training. I don't think that's enough. There needs to be more time for training on an annual basis, and it needs to take employees and employers through the policies so they understand exactly how they work. You need to take them through the definition of harassment so they understand exactly what it is, and they need to understand what the consequences are if they are complicit in harassment or perpetrate it in any way.
On March 26th, 2018. See this statement in context.