people, mainly Lebanese. The proximate cause of the Israeli invasion was the Coastal Road massacre that took place near Tel Aviv on 11 March 1978. On that day, 11 Palestinian Fatah members led by the 18-year-old female fighter Dalal Mughrabi travelled from Lebanon to Israel, where they killed an American tourist at a beach before hijacking a bus on the Coastal Road near Haifa; the group later also hijacked a second bus that was bound for Tel Aviv. After a lengthy chase and shootout, 38 Israeli civilians, including 13 children, were killed and 76 were wounded. Course of fighting On 14 March 1978, Israel launched Operation Litani, after the Coastal Road Massacre. Its stated goals were to push Palestinian militant groups, particularly the PLO, away from the border with Israel, and to bolster Israel's ally at the time, the South Lebanon Army, because of the attacks against Lebanese Christians and Jews and because of the relentless shelling into northern Israel. The area south of the Litani River, excepting Tyre, was invaded and occupied in a week long offensive. The operation began with air, artillery, and naval bombardment, after which IDF infantry and armor forces, comprising about 25,000 soldiers, entered south Lebanon. The Israelis first captured a belt of land approximately 10 kilometers deep, by launching a ground attack on all PLO positions along the Lebanese border with Israel. The ground forces were led by two division commanders, and attacked simultaneously along the entire front. Paratroopers landed from helicopters to capture all the bridges on the Litani River, cutting off the possibility of retreat by the PLO, and later expanded north to the Litani River. The IDF did not succeed in engaging large numbers of PLO forces, who retreated to the north. Many Lebanese civilians were killed by heavy Israeli shelling and air strikes, which also caused extensive property damage and internal displacement. According to Augustus Richard Norton, professor of international relations at Boston University, the IDF military operation killed approximately 1,100 people, most of them Palestinian and Lebanese. According to IDF reporting and internal investigation, at least 550 of the casualties were Palestinian militants initially holding the front line and killed by the IDF ground operation. According to other sources about 2000 Lebanese and Palestinian were killed. Estimates for the number of people displaced by the military operations range from at least 100,000 to 250,000. Syrian troops deployed inside Lebanon,