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Smoke Detector.
Gunnery Sgt. Jhimelle Sepulveda, training chief with a fire fighting unit on Camp Pendleton, California, emerges from a fire training facility during an exercise conducted by the Camp Pendleton Fire Department and the Marine Corps Air Station Camp Pendleton’s Aircraft Rescue Fire Fighting unit on a controlled burn training facility. The training was designed to teach firefighters how to prevent rapid combustion of burned materials in rooms and structures. Original public domain image from Flickr
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