How Seattle's 911 Dispatch System Actually Works
Published April 24, 2026 · 12 minute read
If you have ever called 911 in Seattle, you may have noticed that the operator on the other end of the line asked you the same question two or three different ways, sometimes seemingly without listening to your answer. There is a reason for that, and it has nothing to do with the operator being distracted. The script the call-taker is following is a triage protocol designed to do two things in parallel: figure out what is actually happening at your location, and figure out which units to send before you finish describing the problem. This article is a plain-language walkthrough of that process, written for a general audience, with the goal of demystifying what shows up a few minutes later on the Seattle Breaking live feed.
The first six seconds: who picks up
Every 911 call placed inside Seattle city limits is routed first to the city's primary public-safety answering point, generally referred to as the PSAP. That center was part of the Seattle Police Department until the City Council voted in 2021 to move it out of SPD; today it is operated by the City's Community Assisted Response and Engagement (CARE) Department. The PSAP is staffed twenty-four hours a day by call-takers, not by firefighters or paramedics. This is a deliberate design choice. The call-takers handle the widest variety of call types and are positioned to decide whether a call needs a police or CARE response or should be transferred immediately to the Seattle Fire Department's dispatch center for fire, medical, or hazardous-materials response.
The first thing the call-taker is doing while they answer the phone is reading your phone number, your wireless carrier's best estimate of your location, and any pre-loaded address information from your wireless or landline provider. On a wireless call this location estimate can be precise (sometimes within meters, when your phone's own location data reaches the 911 center through services such as RapidSOS) or it can be a several-block ellipse. On a wireless call the call-taker usually does not see your name. They do see your callback number.
The script: it isn't a script
Medical calls in Seattle are triaged using Criteria Based Dispatch (CBD), a set of guidelines King County EMS developed in 1989 and put into use in 1990; police calls follow their own call-type and priority rules. The medical guidelines are criteria-based: each answer you give routes the call-taker to the next branch of questions. A reported "person not breathing" routes one way; a reported "shortness of breath" routes another. The branching is deliberately tight so that two call-takers handling the same situation produce roughly the same dispatch outcome.
The reason it sometimes feels like the operator is not listening to you — for example, when you have already said "my husband is having chest pain" but they ask whether he is conscious and whether he is breathing normally — is that the protocol forces them to confirm specific facts before they can pick a code. The code, not the narrative, is what triggers the dispatch.
Criteria: turning words into a code
By the end of the triage, the dispatcher has matched the call to a specific criterion — a set of signs, symptoms, or mechanism of injury — and that criterion determines the level of care the patient is likely to need. The central decision is between an Advanced Life Support (ALS) response, meaning paramedics, and a Basic Life Support (BLS) response by EMT-trained firefighters. Critical emergencies, where paramedic care within minutes can change the outcome, get ALS; less critical ones get BLS. Each criterion carries an Initial Dispatch Code, which lets King County EMS compare what was dispatched against what patients turned out to need and track "oversends" and "undersends" of paramedics.
Every code maps in the Computer-Aided Dispatch system (CAD) to a "response plan" — a pre-defined list of units to send. A call that meets ALS criteria brings a medic unit (paramedics), usually alongside a closer engine or aid unit that can start care first. A call that meets only BLS criteria might get a single aid unit or engine. The point is that the response is pre-decided by the protocol, not improvised by the call-taker.
What happens inside CAD
The CAD system is the central nervous system of the entire operation. Once a call has a code and a response plan, CAD examines the current locations of every unit in the city in real time, predicts which ones can reach the call address fastest, and dispatches them. Locations come from automatic vehicle location (AVL) equipment in the responding vehicles, transmitted over the city's mobile data network.
The dispatch itself is a tone alert to the appropriate station's house alarm system (for SFD) plus an MDT — mobile data terminal — message to the unit's in-vehicle screen. Units do not need to wait for a voice radio dispatch to know where they are going; the CAD message arrives at the station within a couple of seconds of the call-taker confirming the address. The voice radio dispatch comes a few seconds later as a sanity check.
It is at this point — the CAD entry — that the event becomes visible in the Seattle Fire Department's Real-Time 911 dataset. Every record on the Seattle Breaking live feed was, at some prior moment, a single CAD record matching the description above. The dataset is generated by an automatic export from the CAD system, with personally identifying fields stripped before publication.
Code 3 vs. Code 1: lights and sirens
You may have heard the term "Code 3 response," sometimes referred to in popular usage as "lights and sirens." Code 3 is the highest-urgency response level: emergency lights on, siren active, exemption from speed limits and stop signs. Code 1 means a routine response — no lights, no sirens, obey traffic laws. There are intermediate levels in some jurisdictions, and the exact terminology varies from agency to agency.
Whether units run with lights and sirens is largely set by the call type and its response plan rather than improvised. This matters for the live feed because Code 3 responses are concentrated in the highest-severity incident types — structure fires, working medical emergencies, MVAs with injuries — and these are the events that tend to draw the visible activity (multiple units, longer on-scene times) you can see on the map.
What happens after the units arrive
Once a unit is on scene, the officer in charge can request additional resources, downgrade the response, or cancel responding units. They communicate back to the dispatcher over the radio, and the dispatcher updates CAD. This is also where the largest gap between "what the data shows" and "what actually happened" opens up. The original dispatch type is rarely updated after the fact. If a "structure fire" turns out to be burnt food and clears within ten minutes, the SFD feed will still show "structure fire." This is why we encourage readers to treat the feed as a description of what was dispatched, not as a description of what was found.
The transfer to fire dispatch
If your call to 911 is for a fire or medical emergency, the 911 call-taker will typically conference in Seattle Fire dispatch rather than simply hanging up on you. This means you do not need to repeat the address. It also means that for a brief moment there are three people on your call: you, the 911 call-taker, and the SFD dispatcher. The SFD dispatcher is the one who applies the medical dispatch criteria for fire and medical calls. The 911 call-taker stays on the line as a safety net.
For calls that are police-only — a property crime in progress, a noise complaint, a welfare check — the 911 call-taker handles the full triage. For calls that overlap (an assault with injuries, an MVA with entrapment), both SPD and SFD will be dispatched and you may hear both on the radio.
The dispatch you'll never see on this site
Not every dispatch shows up in the Seattle Fire Real-Time 911 or SPD Call Data feeds. Specifically, the City does not publish:
- Sensitive calls related to ongoing investigations, sexual assault, juvenile incidents, or domestic violence at certain stages.
- Calls involving certain protected addresses (e.g., domestic-violence shelters).
- Calls flagged for administrative review prior to release.
- The full dispatcher-unit conversation. Audio is only available through third-party scanner services like OpenMHz and Broadcastify, and only for unencrypted frequencies. Since 2026, SPD and Seattle Fire have encrypted their tactical channels, which are not publicly listenable; their dispatch channels remain open.
What you see on Seattle Breaking is everything the City has chosen to release, no more and no less. The choices the City makes about what to release have changed over time and will change again. The current rules are visible in the open-data portal's data policy documentation.
How long does the whole pipeline take?
From the moment a 911 call hangs up to the moment the corresponding record appears on the public dataset is typically several minutes for fire and medical calls; the City refreshes the fire dataset every five minutes. Police data lags much further, because the SPD Call Data dataset is updated once a day. From the dataset to the Seattle Breaking display takes another sixty to ninety seconds. So when you see a fire pin appear on the map, the actual dispatch usually happened several minutes earlier.
One more thing: the 911 system is fragile
The dispatch pipeline described above relies on a chain of systems — wireless carriers, the PSAP, CAD, AVL, the export pipeline, the open-data portal, our backend, your browser. Any one of them can fail, and during storms and carrier outages some of them occasionally do. If you ever cannot reach 911, the SPD non-emergency line at 206-625-5011 and the SFD non-emergency line at 206-386-1400 are alternates for non-emergencies. For active emergencies during a 911 outage, neighbors and physical signaling are sometimes the only options.
That fragility is also why we are very firm in saying Seattle Breaking is not, and will never be, a substitute for emergency reporting. The feed exists to help you understand the city around you after the fact — not to make decisions in the moment.