3 ms·
Battery powered smoke detectors as we now know them came out in the 70s.
by alphabettsy 5y ago
Battery powered smoke detectors as we now know them came out in the 70s.
- handmodel 5y agoI guess my larger point is if risk of death by fire gets cut in half because of variables other than extra staircases - then the benefit of adding extra staircases gets cut in half while the cost remains the same (or even increases).
- kube-system 5y agoAssuming that they are independent factors. In many instances, a life may be saved by the interaction of two variables. Signaling and egress often contribute in complementary functions.