What should occur first when the last victim of a disaster has been treated in the emergency department

Determine if the needs of all organization departments have been met

Explanation:

Disaster response include different community resources such as fire brigade, environmental engineers, police, transportation and housing experts, and medical providers.

Medical providers or hospitals play an important role in the disaster response as they are responsible to treat the injured people. Each hospital should be ready for the natural disaster treatments and their first step when the last victim got treated is to determine if the needs of all organization departments have been met or not.

Because treatment in the emergency department is not pre-planned and for treatment, it is important to check first that all requirements for treatment should be met till the treatment of the last victim.

Hence, the correct answer is "Determine if the needs of all organization departments have been met".