I feel like the ambulance accident call has a disproportionate number of patients. Essentially ambulances only guarantee two to three occupants at a time (if they are in service/have a patient). I do agree that there is a high chance of injury for anyone in the patient compartment area and at the minimum, the patient in the rear of the ambulance will need to have transport continued by another unit, however, I find that most of my ambulance accidental calls if not have the max 6 at all times.
I would recommend reducing the patients to a minimum of 1, max of six still, and a 100% chance of transport for at least one patient. I would also like to recommend the addition of battalion chief and EMS Chief responses (if someone has them, not to require the generation of the call for lower-level players).
While this may not necessarily be a Mass-Casualty response this is a high-profile event that would spike the interest of supervision and for an ambulance to be involved the EMS Chief is likely going to need to be involved in a reporting process, etc.