On foot or riding donkey carts loaded with belongings, a stream of people flowed into Deir al-Balah — a town that normally has a population of around 75,000. It has been overwhelmed by several hundred thousand people driven from northern Gaza as the region was pounded to rubble. Because UN shelters are packed many times over capacity, the new arrivals set up tents on sidewalks for the cold winter night. Most crowded onto streets around the town’s main hospital, Al-Aqsa Martyrs, hoping it would be safer from Israeli strikes.