Pakistan, Sept. 17 -- Rescuers in Gaza City were still digging through concrete on Wednesday after a war-damaged apartment block in Tal al-Hawa collapsed overnight, killing at least 20 Palestinians, including children. Dozens remained missing. Families had returned to the building despite warnings about its condition because, like thousands of others across Gaza, they had few places left to go. The building did not fall during an air strike. Damage inflicted earlier had left it standing just long enough to become somebody's home again.

That says much about Gaza today. Around 2,000 damaged buildings are still inhabited, while UN officials estimate that some 400 structures are at risk of collapse. Winter will make many of them more dangero...