Flash over is a nature of fire. Ignoring to fire alarm, pretending not to hear, or even making joke when hearing the alarm sounded is a nature of human behavior in a building.
This is very common observation regarding fire drill,
Most of the service providers emphasize on how to fight the fire. It is good to make people feel no fear when to put a small fire out with portable fire extinguisher. However, most of training not address the danger of smoke and toxic gases generate from combustible material. Office Furniture, full of wood products, polyurethane, fabric, plastics, and so on. All of them when burn, give off toxic gases that can knock you down in a few minute.
Learning how to carry an unconscious victim out off a fire is fun but in the real life, not many people have a chance to do that but being victim to be carried out instead.
Most of fire drill not give you a caution of using fire escape stairwell. Most people have a chance to walk down the building through the stairwell one time per year. Unknowing that the safe stairwell need to be kept clear from obstructions, well lit, and most importantly, free from smoke. Believe of not, most building management fail to do such a thing,
Poor maintenance
Poor housekeeping
Poor emergency planning
Poor corporation
All of these are great combination to the fire in a Highrise building.
Toxic Gases in a building fire
A small fire, growing from wall socket due to electrical false will grow into a larger fire. Temperatures rise up from hundred degree to 200-600 degrees in 4 second. That is a situation where we called "Flash Over". It means that room is now filled with toxic gases. Some of them can be ignited and exploded. People in the building still not move. They are too busy to react to fire alarm.