What is the main reason doors should be closed during a fire event?

• A. To contain heat and smoke to the origin area.
• B. To ensure faster spread.
• C. To reduce oxygen.
• D. To block exits.

Answer: (A)

Closing interior doors during a fire relies on compartmentation: doors act as barriers that slow the movement of heat, flames, and smoke from the origin area into other parts of the building. When doors stay shut, the fire’s energy is contained, so adjacent rooms stay cooler and ventilated less, making it harder for the smoke to travel and for the fire to grow as quickly. This buys crucial time for people to evacuate and for firefighters to control the scene, and it helps keep escape routes clearer and more tenable. It’s not about speeding up the spread or blocking exits; those outcomes would be dangerous. Narrowing the door openings slows the fire’s reach and preserves safety in areas that people rely on to get out or to work from.