My friend Beth bought a carbon monoxide detector after living in her place for about six months. The moment she plugged it in, it started going off. There are all kinds of warnings on the package not to ignore it when it goes off, so after worrying for a bit she dialed the local information phone line. She told them that her new carbon monoxide detector was going off, so they said they'd transfer her call. They transferred her to 911, and she told them that she didn't consider it an emergency, but her carbon monoxide detector was going off. They sent the fire department. So she waited a few minutes until she heard the sirens, and then a bunch of firemen burst through the door. The moment they got into her place, all the carbon monoxide detectors on their jackets started going off. Turns out it was an emergency.