The operator (officer) who answered Your call would:
ask You to describe the accident which You are involved in and answer his questions;
promptly assess the nature of the threat and would determine what type of response You need;
instantly dispatch appropriate emergency services that would head to the emergency location to provide the assistance;
if necessary, connect You with the operators of the appropriate emergency agency (police or ambunace).
It often happens that several people report the same accident. So don’t be surprised if the operator only specifies whether You have more additional and useful information about the accident and ends the conversation. He acts in such way to free up telephone lines faster and to ensure prompt answer of the next emergency call.