Hello,
I was thinking on a Metro Fire, i don't know much about metro's in USA, but maybe it will be a nice call.
Think off a train part caught fire, of a kiosk inside the metro, or a power station or something.
We can even think about victims who has smoke inhalation, even we can use the police for a (virtual) evacuation.
I don know how many units there is needed so i thought like 2 trucks, 2 ambulance 3 police 1 battalion chief, maybe a higher person if we have that in the system( like a ELW)