The first stage of the Intifada was a response to an incident at the Erez checkpoint, where an Israeli military vehicle hit a group of Palestinian laborers, killing four of them. However, within weeks, following persistent requests by al-Wazir, the PLO attempted to direct the uprising, which lasted until 1991, or 1993, according to various authorities. Al-Wazir had been assigned by Arafat the responsibility of the Palestinian territories within the PLO command. According to author Said Aburish, he had "impressive knowledge of local conditions" in the Israeli-occupied territories, apparently knowing "every village, school, and large family in Gaza and the West Bank". He provided the uprising with financial backing and logistical support, thus becoming its "brain in exile." Al-Wazir activated every cell he had set up in the territories since the late 1970s in an effort to militarily back the stone-throwers who formed the backbone of the Palestinian revolt. He also used the opportunity to reform the PLO. According to author Yezid Sayigh, al-Wazir believed that the Intifada should not have been sacrificed to Arafat solely for use as a diplomatic or political tool.