Final answer:
In high-rise downtown shopping malls, atriums pose significant risks for firefighters during a fire, as they allow for the quick spread of smoke and flames.
Step-by-step explanation:
In large downtown shopping malls that are multiple stories high, atriums create trouble spots for firefighters because fires can often occur within these open, central spaces. Atriums typically have a large vertical opening extending through several floors of the building and can allow for rapid spread of smoke and fire, making firefighting efforts more difficult. They also pose potential risks for egress, as people may become trapped on upper levels if evacuation routes such as stairwells are compromised.