Under what condition should an investigator enter a burning structure?

Entering a burning structure presents significant risks, including the potential for flashovers, structural collapse, and exposure to harmful smoke and toxic gases. Fire suppression personnel are trained to handle emergency situations and understand fire dynamics, which makes them essential for ensuring the safety of any investigator entering a burning building.

By being accompanied by fire suppression personnel, the investigator not only benefits from their expertise in managing the fire conditions but also has immediate access to assistance should a dangerous situation arise. Firefighters can assess whether it is safe to enter and can provide protection and support during the investigation.

The other options, while they might suggest a team approach, do not prioritize the critical need for safety in an active fire situation in the same way as having dedicated firefighting personnel alongside. They would not guarantee the immediate safety measures that trained fire suppression personnel can offer in such hazardous environments.