Which factor may lead to a possible building collapse?

The option suggesting the use of master streams is a valid concern in the context of potential building collapse. Master streams refer to large volume streams of water delivered at high pressure, commonly employed in firefighting operations for extinguishing large or well-advanced fires. The application of large amounts of water, particularly in a short period, can significantly increase the weight of the structure due to water saturation.

In cases of structural fires, the building materials may already be compromised by heat, weakening their integrity. Applying master streams directly onto a structure can inadvertently increase the risk of collapse as the additional weight and force exerted may exceed the structure's ability to support itself, especially if the fire has already weakened load-bearing elements.

The other considerations, while relevant to fire operations, may not directly lead to building collapse in the same way. Heavy timber construction, although it presents certain risks, often has different characteristics than other materials; it can even be more resilient under fire conditions up to a certain point, depending on the fire involvement. A combination of direct and indirect attack focuses on mitigation strategies and does not inherently pose a collapse risk.

Thus, while master streams are a practical firefighting tool, their improper or excessive use in certain structural scenarios can lead to an increased