THE Sikh community in Canada is in a state of shock. No one can understand why Mark Vijay Chahal gunned down his estranged wife, Rajwar Gakhal, and eight members of her family. "I am stunned. This has never happened in our community," says Surjit Singh of Toronto. "There must have been something he could have done if he was unhappy. Why kill?" This question is being asked all across the country as Canadians take in the horrific details of the massacre in Vernon, the second-worst mass murder in Canadian history.