Open this photo in gallery: An observer stands amid mattresses and beds, part of an installation called Empty Beds initiated by survivors of Kibbutz Nir Oz and the families of hostages held in Gaza, at a public square in Jerusalem on Oct. 30.RONEN ZVULUN/Reuters Family members of people who were abducted by Hamas flew to Ottawa on Monday to meet Prime Minister Justin Trudeau and make heartfelt pleas for greater efforts to free their loved ones. Among them was Aharon Brodutch, who lives in Toronto. At a news conference after the meeting with Mr. Trudeau, he held up photos of...