It was an ordinary evening at the Arab-owned, Jewish-operated Café Hawaii on the outskirts of Tel Aviv. Jewish couples crowded the dance floor. Alongside, the River Yarkon flowed quietly between its eucalyptus-lined banks. "Jeep," a comedian, stepped to the microphone, opened his mouth to sing, and a grenade exploded among the dancers. From darkness surrounding the brightly lighted open-air café came the flash and rattle of automatic rifle fire. Four Jews were killed, twelve wounded. Survivors said the attackers were Arabs. If so, the raid was the first serious attack by Arabs on Jews since 1939.