The primary risk factor for residential fires is unattended cooking. To prevent accidents, one must never leave cooking unattended, take care not to overheat fats, and never attempt to extinguish a grease fire with water.

noli's read

This warning is based on particularly robust public safety data. According to observational statistics from the National Fire Protection Association (NFPA), cooking is indeed the leading cause of residential fires and associated injuries, accounting for nearly half of these incidents. These consensus reports indicate that inattention is the primary triggering factor for these fires. From a physics perspective, the prohibition against using water on a grease fire is based on proven thermodynamic principles. Water, being denser, sinks below the superheated oil and vaporizes instantly while expanding dramatically. This projects droplets of burning oil throughout the room in the form of an aerosol, spreading the fire immediately. It is therefore validated to extinguish this type of fire by cutting off the heat source and smothering it with a metal lid.

the sources

No named source held this one up — that absence is part of the verdict.