As a safety officer at a multistory residential building fire, which issue is least likely to be a concern?

In the context of a multistory residential building fire, the likelihood of an explosion occurring is generally lower compared to other concerns such as fire spread, structural collapses, or chemical spills. Residential buildings typically do not contain the same concentrations of volatile materials or hazardous chemicals that might lead to explosions.

Fire spread is a primary concern due to the potential for flames to move rapidly through floors and compartments, creating immediate danger to the occupants and firefighters. Structural collapse is also a critical issue, particularly in multistory buildings, as weakened floors or walls can create hazards for both residents and emergency responders as they navigate the scene. Chemical spills may be a concern if there are substances present, such as in units where residents may have stored cleaning supplies or other hazardous materials, but this would not be a given in every residential scenario.

Overall, the dynamics and materials within residential buildings make fire spread and structural integrity pressing concerns while the likelihood of an explosion is less pronounced, making it the least likely issue of the ones presented.