In the late 1950s, what type of doors were introduced that can be compromised by fire within minutes?

Hollow core doors were developed during the late 1950s as a lighter and less expensive alternative to solid wooden doors. They are constructed with a thin layer of wood or another material that surrounds a hollow interior. This design makes them less durable and more vulnerable to damage, including from fire. In the event of a fire, the structure of a hollow core door does not provide substantial resistance, allowing heat and flames to compromise the door’s integrity within a matter of minutes.

While wooden doors might also be affected by fire, they typically offer more resistance compared to the lightweight design of hollow core doors. Sliding doors and steel doors, depending on their construction, might also differ significantly in terms of fire resistance. Steel doors, when properly engineered, can provide significant fire protection and are often used in situations where fire safety is a major concern. However, hollow core doors are particularly known for their quick compromise in a fire, making this answer the most accurate in the context of the question.