We had a fire last winter in a detatched garage. A tractor with an electrical problem was the cause but that is a different story. After a quick knockdown, I sent a crew in to open the overhead/garage door using the manual release. The crew came back out and said they couldn't find the cord in the smoke. I sent in another crew with better light and a halligan. Long story short the cord had melted off. Lesson learned, Most of my crew has replaced the NYLON cords in our own garages with short lengths of chain. This should make it easier to vent in the event of a fire.