MONTREAL - The Monday arson attack on a Montreal Jewish school was carried out to avenge Israel's assassination of Hamas founder and leader Sheikh Ahmed Yassin, according to a letter found at the scene. Quebec's French-language TVA television network reported the letter denounced recent Israeli attacks against Palestinians, including the killing of Yassin. The letter noted the arsonists intended the attack as a warning and did not intend to harm people, Montreal media outlets reported. But this is just the beginning, the letter warned, adding that if Israel continues its "crimes" in the Middle East those then those responsible for...