One night when I was at university, I became a hero by chance. A girl had decided to take her own life by cutting the gas line in her apartment. Fortunately, I smelled it. With the help of her roommates, I called the fire department, opened the windows in the stairwell to circulate air, and to wake up everyone in the building so it could be evacuated. All of this was done without turning on lights or sounding bells, in case of causing sparks.