The longest journey begins with a single step.
Lao Tsu, Tao Te Ching
Whether making the initial distress call to rescue centers, or reporting an accident after the fact, there are certain facts and points that should always be addressed to ensure that the rescue personnel are alerted and are provided with all the necessary information they need to effectively provide and coordinate a rescue response. The reporting individual also needs to be prepared to provide their name, address, current location and contact information like a call back telephone number.
So, when reporting an accident, always remember to include the following information:
Description of the incident: Coming under the what, a full discription of what happened, who was involved and their last known location. Also include where the person's vehicle is located, as well as a full description of it (make, model, year, license plate - all possible information). A description of the last known location's weather, conditions and trail information is also helpful, if not vital, for rescue personnel to make an informed decision about approaching a potential rescue effort.
Any information rescue personnel might find useful should also be mentioned, so as to give rescuers a better picture of who they are attempting to find. including what gear/tools the person might have been carrying, clothing descriptions and equiment possessed (for example snowhsoe, packs, map, compass, lights, extra food/water), footwear, planned itinerary, medical information, the person's outdoor experience, etc.