Fire safety in Israel and in America are very different things.
The buildings in Israel are made of stone and poured cement, and are not flammable. That is why they are not very concerned about smoke detectors.
Once when I was in yeshiva, the heater in the bathroom started making funny noises and breathing fire on Friday night. So I used a hanger to shut it off with a shinui. When I mentioned it to a rebbi in the morning, he told me I should have let it burn. He said that the buildings are non-flammable, and fires are not considered pikuach nefesh in Israel.