When a gunman stormed into a kosher supermarket in Paris, seizing hostages and killing four people, Julien Catan felt tremors all the way to Montreal. A Paris native, he had walked the streets around the Hyper-Cacher market thousands of times. His fiancée’s mother had been shopping there 20 minutes before it was attacked. “What happened in January was a real shock, like never before,” Catan said in an interview. “I think the impact it had is very profound, and I think the Jewish community has taken a real hit.”