From Longform.org, a story of a fire in an abandoned warehouse – The Perfect Fire:
The message that there might be people inside was relayed over the fire-department radios. Brotherton and Lucey walked back across the roof to the AB stairs, tromped down one flight, and started searching the top floor for people. Routine. At 6:22, only the thinnest haze of smoke hung in the corridors. More than two dozen men were in the warehouse, looking either for homeless people or flames. Each man had a tank strapped to his back filled with oxygen compressed to forty-five hundred pounds per square inch–enough for thirty minutes of relaxed breathing, half as long humping through a burning building–and connected to a plastic face mask. But the air was so clear that no one had bothered to put his on.
Chills, and heart-wrenching.