Which of the following construction features increases the risk of early collapse?

Large open unsupported areas significantly increase the risk of early collapse in construction during a fire. This design feature lacks adequate support structures, meaning that if a fire occurs, the integrity of the building can be compromised more quickly. In the absence of walls or other structural supports, the loads that the roof and upper floors must carry can become unmanageable as the materials weaken from heat exposure.

While reinforced concrete walls provide strength and rigidity, fire-resistant doors are designed to slow the spread of fire and protect against heat damage. Additionally, diagonal bracing is commonly used in structures to enhance stability and support, effectively preventing collapse. In contrast, large unsupported spans offer minimal resistance to the stresses caused by fire, making them particularly vulnerable and dangerous in emergency situations.