A released hostage told The Associated Press last month that she and over two dozen other captives had been held in Nasser Hospital. International law prohibits the targeting of medical facilities; they can lose those protections if they are used for military purposes, though operations against them still must be proportional to any threat.
Before the hamas apologists chime in perhaps you might consider that the Israeli were not fighting a pitched battle for days to enter this hospital with ghosts.
Hamas again seems to have militarised a hospital (a war crime) and attacking a militarised hospital is in fact not a war crime. Recovering their dead hostages is besides the point.
Loaf is baking well