DEIR AL-BALAH, Gaza Strip — Strong winter winds collapsed walls onto flimsy tents for Palestinians displaced by war in Gaza , killing at least four people, hospital authorities said Tuesday. Dangerous living conditions persist in Gaza after more than two years of devastating Israeli bombardment and aid shortfalls. A ceasefire has been in effect since Oct. 10. But aid groups say that Palestinians broadly lack the shelter necessary to withstand frequent winter storms. The dead include two women, a girl and a man, according to Shifa Hospital, Gaza City’s largest, which received the bodies. The Gaza Health Ministry said Tuesday a 1-year-old boy died of hypothermia overnight, while the spokesman for the U.N.'s children agency said over 100 children and teenagers have been killed by “military means" since the ceasefire began. Meanwhile, Israel’s military said it exchanged fire Tuesday with six people spotted near its troops deployed in southern Gaza, killing at least two of them in western Rafah. Three members of the same family — 72-year-old Mohamed Hamouda, his 15-year-old granddaug