Was stationed at [REDACTED] toll plaza for hardware support. One of the cashiers in the lanes shouted over the intercom she got a fire in her heater.
Now in those days the airconditioner also act as a heater (elements). In those days an aircon that reverses itself and gives off heat instead of cold was very, very rare.
When the alarm was called out, I was in the control room busy with my daily tasks. It amazed me still that nobody acted on that... I relocated myself quickly from the control room to the lane in question, grabbed the fire extinguisher (powder-based), and checked for the fire. Yup, flames. And smoke.
And emptied the extinguisher completely on the fire. :) Was great fun. Powder everywhere. :)
As a precaution, I also turned off all power to the lane, and the lane was closed.
When the aircon techies came out, we had a shufty at the culprit. It was an electrical connection on the heater element which was not fastened properly, it overheated and started to burn the plastic covering the wire.
Would've got a lot worse had I not acted promptly.
Anon because I still work for the same company.