How did the Press know to be there? (go to about 0:35 in). Why was the building the one being watched? That fellow already had two cameras set up.
Historically the Israeli’s have given a warning when a building is about to be attacked - both via radio and via a “tap”, a small charge dropped on the roof to allow evacuation before the main strike a few minutes later.
That did, of course, allow the probable targets to escape - they news today is they have announced that no further advance warning will be given - and Hamas has said a hostage will be killed for every attack made without a warning.
Example of a “tap”