So you've called 911 and reported an emergency. Now what happens?

For simplicity, we'll break down the various 911 calls into six types:

Each type is addressed below. Note that these descriptions may discuss what happens at different dispatch centers, based on who answered your 911 call.

Vehicle Accident or Traffic Collision

If your 911 call was routed to CHP, they will ask for the location of the accident and details. They will generally send a CHP officer to the scene, and will request EMS (ambulance) and fire resources from the proper local jurisdiction if they might be needed.

If your call was sent to a regional dispatch center instead, they will probably request CHP or sheriff, as well as EMS and fire personnel. Should your call wind up at the Felton Cal Fire dispatch center, they will work with Netcom to get an ambulance coming to the accident scene, in addition to fire and CHP or sheriff if needed.

Note that accidents on major roadways often result in auto-aid or mutual aid requests going to neighboring jurisdictions as well.  Example: an accident on 17 near the Summit may get a response from: Santa Cruz County Fire (both from Cal Fire stationed at Burrell and the Loma Prieta Volunteers), Santa Clara County Fire (stationed at Redwood Estates), and from Scotts Valley Fire. Any given call won't necessarily get all three jurisdictions responding, depending on how well the reporting party describes the location.  "North of Summit" will probably only get Santa Cruz County Fire and Santa Clara County Fire, while "south of Summit" will probably get Santa Cruz County Fire and Scotts Valley. But it is common to get all three when the actual location isn't well understood at the time of dispatch, or when the dispatcher thinks the nature of the accident may require that many personnel to handle the situation or provide for scene safety.

Various roads and locations get various responses, depending on the exact location and the availability of personnel. It is possible, for example, that the Santa Clara County Fire people are all busy at some other incident, and Cal Fire and LPVFR wind up responding to an accident on 17, north of Summit, all by themselves. That's not generally supposed to happen, but if Santa Clara is busy, it can.

As a rule, the ambulance dispatched to an accident scene comes from the county the accident is in. However, because our area spans a county line, patients often wish to go to a particular facility for treatment. EMS tries to accommodate those requests, but they are subject to approval from the medic supervisor, and may be limited by the number of ambulances available and the severity of the injury or illness. If you have a preference for where an ambulance takes you, state that to the first responder to arrive on scene. They may not be able to fulfill your request, but at least they can pass it on.

If the accident is severe, it can automatically cause an air ambulance to be launched as well. Air ambulances (helicopters) usually come from one of two local sources: CalStar or Stanford Life Flight. Both will carry a patient to a local trauma center, all of which are in Santa Clara County. Air ambulances, however, don't land in fog or other inclement weather, and they can all be busy, so they aren't always available. There are a set of criteria that indicate to the dispatcher that an air ambulance is to be launched. They include things like airbag deployment in a car accident, and a "vehicle vs. pedestrian" description. In addition, the dispatcher can order an air ambulance based on various other factors as well. There is no charge if an air ambulance is launched and the patient turns out not to need it.

The various resources all arrive on scene as rapidly as possible, and the order of arrival can vary based on what is available and where they are.  Often it's fire personnel who arrive first, because they are closest.  In the 95033 area that means Cal Fire from Burrell station or Saratoga Summit station, volunteers from Loma Prieta Volunteeer Fire & Rescue, Santa Clara County fire from Redwood Estates station, and Scotts Valley fire.  Ambulances come next, since they are generally pretty far down the hill. CHP or sheriff can arrive at any time depending on location and availability. Air ambulances generally arrive after fire personnel, but usually only land at specified landing zones, and generally have a fire crew present when they land to keep bystanders out of the way, etc. (Safety tip: never approach a helicopter without an escort from the crew. Stay well clear at all times.)

Also note: Scotts Valley and Redwood Estates fire engines have a paramedic on board, and can thus offer ALS (Advanced Life Support) services, like giving the patient certain drugs, starting an IV, etc. Santa Cruz County Fire  (both Cal Fire and the volunteer companies) do not have ALS capabilities, only BLS - Basic Life Support - so they can perform CPR, use an AED, insert an airway, take vital signs, bandage for bleeding, etc. but they cannot administer medications. If no fire engine with a paramedic is dispatched to an incident, the first paramedic on scene will come from the ground or air ambulance.

In general, accident scenes are commanded by the law enforcement officer present - CHP or sheriff. Fire and EMS personnel have specific roles - provide medical aid, put out fires, secure vehicles - but they also have to do what the law enforcement officer wants. If that means getting vehicles off the road quickly to get traffic flowing, so be it. Alternately they may need to keep the scene as is for investigation, particularly if a fatality is involved.

Patients at an accident scene are treated by the medical personnel available, but are not required to go to the hospital, and there is no cost to patients for treatment provided at scene if they chose not to go to the hospital. The technical term for declining treatment is "AMA", for Against Medical Advice. If you were potentially injured don't want to be taken to a hospital you will be asked to sign an AMA form and released from the scene when law enforcement officers have no questions for you.

Unresponsive or unconscious patients are assumed to need immediate medical care, given emergency treatment at scene, and are taken to a hospital or trauma center.

If you have a particular medical condition it is important to have a medic alert bracelet or other indication so that paramedics and doctors know about it if you cannot communicate. You should also carry something indicating your emergency contacts in your wallet or purse, so someone who can make medical decisions for you can be found and contacted more quickly should that be needed.

Medical Aid

A medical aid call is very much like an accident call, except that the CHP and/or sheriff don't come unless they are specifically requested for some reason. Generally that means some sort of high risk situation - assault, domestic violence, suicide attempt, weapons present, etc.

Fire and medical personnel are generally not allowed to enter a dangerous situation and are instructed to wait nearby (called staging) until law enforcement has declared the scene secure for EMS and others to come in. This is another area where specific training and responsibilities are separated and the right personnel are required on scene. The 911 dispatcher will work with you to determine what agencies are needed at your scene and get them coming to you as quickly as possible. Please don't think poorly of fire department or medical personnel for waiting in these cases. They are following orders created to reduce the chances of them becoming additional victims themselves.

Something Requiring Law Enforcement

911 calls for things that specifically require only law enforcement are handled by the regional 911 dispatch center - sending the proper agency to you. As with other calls, they will ask for the details and send the resources required.

And as with all 911 calls, there are various levels of urgency and priorities. Sheriffs deputies will be sent to violent incidents and serious crimes before they will be sent to tell someone their party is too loud. The number of deputies on duty and the number of incidents going on in the county can extend the time it takes for a deputy to arrive.

Once the deputy arrives, what happens depends entirely on the situation. They may or may not contact you - the reporting party - and how the situation is resolved is beyond the scope of this document.

Note that in circumstances where they feel it justified, it is possible for the sheriff to charge a property owner for repeated visits for the same issue. If your kids have loud parties every weekend and your neighbors call them in every time, eventually the sheriff could send you a bill.  Apparently it doesn't happen often, but it can happen.


Smoke with no obvious cause inside a residence is considered a fire by fire personnel and they go straight to the scene with lights & sirens - "Code 3".  Generally the dispatcher will advise residents of a home to evacuate in these cases. Firefighters will size up the situation when they arrive on scene. If there is no obvious source of smoke or flame, they will investigate inside the house and talk to the residents, trying to establish what happened. They may use a thermal imaging camera to look for hot spots if they think a fire might be inside a wall, attic, chimney enclosure, or other hard to see space.

There are many possible causes for this kind of situation - electrical fires, cooking fires, chimney fires, dropped cigarettes, and so on. Firefighters will remain on scene until they find the issue, or they determine that they cannot find the source of the smoke and no one knows what it was.

911 calls for the smell of smoke (only) outside a home are called "smoke checks" by fire personnel. Because smoke can drift long distances - hundreds of miles in the case of large fires - and because no specific fire has been reported yet, these calls are run "Code 2" - normal driving, no lights and sirens.  Only if a fire is found or reported are they escalated to Code 3.

Smoke checks are particularly common in the winter, when backyard burns are allowed (in Santa Cruz County only), and when people are heating their homes with wood fireplaces. Smoke in the summer is more worrisome, and firefighters will investigate to the best of their ability. When you report smoke, the dispatchers are looking for all the information they can get: where it may be coming from, is it visible, the color, even how it smells.

Fire personnel will drive to the location where the smoke was reported and see if they can find it. Often it is transient, and is already gone when they arrive, particularly with smoke from vehicles or barbeques being started. Depending on the situation - particularly if they can still smell it - they will drive the roads in the area looking for a source or problem. They may also go to the address of the reporting party to get more information. This is particularly common if the report is of smoke seen from a distance.

Smoke can be difficult to track down even in the best of circumstances, and many of our summer evenings are cool enough that some residents use fireplaces to warm their homes. Barbeques and fire pits are other sources of smoke that can result in 911 calls that don't turn out to be fires.

Fires can actually be difficult to find as well. Power lines may fall well away from homes, for example, and the resulting fire may creep along the ground for a long time before the smoke from it is noted by anyone. The smoke from such fires may be thin and diffuse, not forming an obvious column and thus being hard to localize. And looking for smoke at night can be nearly impossible, as even a well defined column can be very difficult to see.

Eventually, if firefighters cannot find a source or lose the scent, smoke checks are ended with the firefighters "checking to their satisfaction" and the "UTL" - Unable To Locate - designation.  But dispatchers keep these reports in mind. Repeated calls for smoke in an area may provoke additional response, checking surrounding areas and possibly bringing in other departments to assist. Smoke that doesn't go away but cannot be found is very worrisome, and firefighters do not stop looking for such things lightly. In some cases a helicopter will be dispatched to fly over the area looking for sources that ground units cannot locate.


Fires elicit a code 3 response from fire personnel. What equipment is dispatched depends on the time of year, time of day, weather conditions, and the nature of the report. The general idea is to send a lot of resource to the scene quickly so those who get there have what they need to keep a small fire from becoming a big one. The dispatch center has a basic dispatch level - low, medium, or high - that determines what they send to any reported fire, but the specific resources sent may be reduced or supplemented as they deemed necessary by the dispatcher. Cal Fire, in particular, staffs their command centers with experienced captains that can make the needed calls to adjust the resources going to a fire based on many considerations.

As an example, during fire season, when conditions are severe, a report of a fire will result in a large dispatch: five fire engines, a battalion chief, aircraft, helicopter, bulldozer, and possibly more. This can be true for a reported structure fire, vehicle fire (where there is a threat to the vegetation), or wildland fire.

Note that after dusk and before a predetermined time in the morning, Cal Fire does not fly firefighting aircraft or helicopters due to safety concerns, so those won't be dispatched at night, even in the worst of cases.

When conditions are less severe - during the winter, when things are damp and fires aren't nearly as likely to spread - the amount of equipment sent to a fire will be smaller by default.

The first equipment on scene - engine, battalion chief, or aircraft, depending - will give a report on conditions back to the dispatch center. Such a report is very concise: how big an area (or structure or vehicle) is burning, what fuel is burning (structure, timber, brush, duff), how fast it is spreading, the location, the wind conditions, any indication of structures threatened, and any changes to the resources needed at the scene.

Example 1: The first engine on scene of a vehicle fire discovers the vehicle is smoking, but it's just an overheated engine. There are no flames and no fire spread. In that report they would probably cancel all incoming resources - possibly except one other engine to file the required report, if the first engine to arrive is from a different agency.

Example 2: The first engine on scene finds a fully involved vehicle fire that has already spread to a nearby hillside with houses at the top of the hill. They might request additional resources - like law enforcement (to evacuate the homes at the top of the hill), aircraft if they weren't part of the dispatch already, and water tenders to supply water to the fire crews working the fire. They might request additional engines if they think the incoming resources aren't going to be enough, and probably a hand crew or two to help cut line around the fire to contain it. They might ask for law enforcement to provide traffic control, PG&E might be called in to shut down power lines, and so on.

Any fire that gets big enough winds up becoming a logistical challenge: those working the incident need to be fed, for example, and breathing apparatus need to be refilled at structure fires, which requires a special truck with the right equipment. Very large fires get specialized incident command teams that travel around the state doing nothing but directing resources to bring fires under control.

Even a small fire can take hours to get contained and controlled.  (Those words have specific meanings: "contained" means a line has been cut or created all the way around the fire, so it should be limited in size to the area inside the line; "controlled" means the fire is out, though undetected hot spots may still remain and flare up over time.)  Often an engine crew or two will stay at a fire scene overnight to be sure it doesn't rekindle thanks to wind and a hot spot. And there may be engines patrolling the fire for several days after it is extinguished, to be sure that roots or stumps weren't hiding additional hot spots.

When firefighters are working on a fire they cannot respond to other incidents that may come up. To avoid that problem, the fire service keeps extra fire crews on staff, and borrows engines and crews from surrounding areas to backfill stations while a large incident is being worked.  Equipment and personnel from Santa Cruz County might staff stations in Monterey while the people normally there are working a fire in LA. And to cover in Santa Cruz County, we might get apparatus and people from Santa Clara county or any number of places farther north. The specifics vary from event to event and how resources are deployed in the state at any given time. Big fires can consume dozens or hundreds of engines and crews from all over the state. Backfilling for all of that can be a challenge, but the various fire services cooperate to make it possible.

Anything Else

There are other reasons that people call 911, of course.  Hazardous material spills, explosions, water rescues, search and rescue operations, and any number of other things. The dispatcher taking the call will request the resources needed to handle the situation, and various departments have specific skills and training to handle parts of such events.

Fire personnel handle initial response to hazardous materials incidents, for example, and can run decontamination stations to clean those affected.  Crowd control is generally the province of law enforcement, and the coast guard handles most water rescue operations.

Every incident is different, but the emergency dispatchers have many agencies they can call upon with the experience needed to respond to whatever is being reported. As you can imagine, it is impossible to address every situation here, but you can get a flavor for how resources are assigned to an incident and the overall flow of what happens over time from the cases documented above.


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