Gathering information to inform situational awareness should help to identify the safest approaches to an unstable or collapsed structure. This should include consideration about the potential for secondary collapse, structural stability and the need for physical protection of emergency responders and casualties.
Secondary collapse
Emergency responders should be briefed about a safe approach to the hazard area, to avoid underground voids and causing secondary collapse. Approach routes and cordons should be continuously monitored, and any updates communicated to all emergency responders. Vehicle movements should be isolated or controlled in areas where this could impact on structural stability.
Avoidance routes should be established that keep emergency responders and casualties away from high-risk areas.
Physical protection
If possible, personnel should try to use or create hard protection barriers. These may exist at the scene, with an example being the use of elements that are structurally sound to define an access route to an unstable area of the structure.
It may be possible to use equipment and shoring techniques to create hard protection, or to build temporary physical barriers that allow emergency responders and casualties to be isolated from the hazard of secondary collapse.