The shrine was destroyed in May this year by Salafi Sunni rebels.
The Salafis destroyed the shrine because they feel people who pray there are praying and worshiping Abraham and not God. Salafis are puritanical (not necessarily orthodox) and seek to dissuade anything that they believe takes away worship of God. In its militant form, Salafis are the Muslim equivalent to the Puritans who stripped the altars, destroyed monasteries, and hunted down priests during the Reformation.
Salafis in general have spent the last twenty years actively destroying land marks because they believe them to be sites of worshiping something other than God. Tombs of Islamic saints, graves of imams, and even old mosques which locals regarded as special have been destroyed in Afghanistan, Mecca and Medina, Timbuktu and elsewhere by Muslims influenced by Saudi and Egyptian Salafi teaching. Sadly, the Shrine of Abraham is the latest victim of aggressive foreign Islam on the local native Syrian Islam.
I fear one day Abraham's Oasis may fall victim to aggressive foreign Islamic thought and actions. Judeo-Christian-Islamic history is being wiped off the map by those who seek to destroy anything they disagree with.