Helen stepped outside her front door to see what the weather was like. It was sunny and warm. That was nice, because for the past two weeks it had been cold and rainy. It had been so cold that she had had to turn her heater on. She was lucky, because her heater worked and she could pay her heating bills.
Some people in Los Angeles were not so lucky. Unable to use their home heater, they placed charcoal into a barbecue grill and lit it. The heat kept them warm, but the carbon monoxide killed them.
This happens almost every winter in Los Angeles. People shut all the windows tight to keep the cold out, then light the charcoal. Soon enough, the oxygen in their home is consumed by the open flames. The family suffocates to death.
Everyone knows that smoke detectors are required in Los Angeles. But many people don't know about, or don't think they need, carbon monoxide detectors. They're not expensive. A $25 investment can save a family from death.
People always think that nothing bad will happen to them; it always happens to "the other guy." So they forget to put fresh batteries into their smoke detectors annually, and they don't bother to buy carbon monoxide detectors.