Gizmodo story on a clever and apparently effective means for Detroit firefighters to respond to fires and other emergencies. The article gives a brief description of this and other "MacGyver" solutions to rousting the emergency responders when the notice of an emergency comes through on their printer.
Yes, that's right - it's the printer (or fax, going by the original Detroit Free Press article) that delivers the original message. But maybe it's just not loud enough???