My friend its_raining_jen just heard some odd beeping. She found it was coming from the carbon monoxide detector. She immediately called 911. As she was opening the windows and pulling on her jacket, the carbon monoxide detector in her bedroom started beeping too. When the firefighters arrived, their personal carbon monoxide alarms went off, and they had to back out and put their masks on before returning.
Jen and Leo are safe thanks to the detector.
If you don't have carbon monoxide detector, get one now. I am adding these to my list of free things for my friends, so if you can't afford one, I'll buy one for you.