Hamas is the cause of all suffering in the Gaza Strip, and they could have put a stop to it anytime in the last six months by simply laying down their arms and releasing all the hostages.
Hamas had to know before hand, that by launching a genocidal attack on Israeli men, women, and children, and rounding up hundreds of Israeli hostages of all ages, that it was not going to go well for the good people of Gaza that Hamas has used for human shields.