The Israeli military said it was looking into the reports. The military denied having attacked the school, as Palestinians claimed, and was probing to find out the source of the explosion.
Jerusalem Post: IAF targets UN-run school; Palestinians: At least 10 killed
I’m going to make some guesses, we’ll see how well they bear out.
1) Weapons were stored in this facility, possibly top Hamas officials were hiding there.
2) The school was warned by phone calls and/or ‘knocking’ on roof.
3) Hamas filled the building with people and would not permit anyone to leave or go up to the roof so that the pilot(s) could see them because Hamas wanted many people to die.
4) The entire episode is a Hamas attempt to create a ‘massacre’ and make Israel ‘responsible’ for it.
5) Hamas is totally responsible.