This has been public knowledge since about 2008, every man and his dog knows this one, that's why there's always armed men inside the hospital when journalists take video. The roof was also used as a launch pad for a rocket, caught on camera by a France 24 reporter if my memory serves me correctly (can't find the articles, Google can't tell the difference between al-shifa and al-ahli so it just shows news about the latter annoyingly).