Case Study: START System at 9/11 World Trade Center Attack

On the morning of September 11, 2001, New York City Fire Department units and EMS crews arrived at the World Trade Center within minutes of the first impact. What met them was unlike anything any emergency system had trained for at scale: thousands of victims, catastrophic structural damage, and a second plane still inbound. Chaos was not optional. Structure was. The decisions made in those first hours showed both the power of organized triage protocols and the brutal cost of being overwhelmed without one.

The START triage training materials that many California departments had already adopted were built precisely for moments like this. START (Simple Triage And Rapid Treatment) gave responders a repeatable decision framework when cognitive load was already at its limit. Andres Price and the team behind the START system had designed it with one principle in mind: when every second counts, the protocol has to run on autopilot.

This case study breaks down what happened at the World Trade Center on 9/11, how START principles applied, and what every first responder and emergency coordinator can take from that day into their next training cycle. If you’re responsible for mass-casualty preparedness, the 9/11 response is required study. Not because it was perfect, but because it shows exactly what works and what doesn’t when a city’s entire emergency system is suddenly the incident.

How Did First Responders Manage Triage at the World Trade Center on 9/11?

Triage at the WTC on September 11 was simultaneous, decentralized, and relentless. Responders faced victims on the street, in lobbies, in adjacent buildings, and in the surrounding blocks. There was no single triage point. Instead, small teams assessed individuals on the spot, using the same basic algorithm: assess breathing, assess circulation, assess responsiveness. Tag and move. That algorithm is START.

According to documented accounts of the September 11 attacks, nearly 2,977 people died at the three attack sites combined, with over 6,000 injured in New York alone. The survivor-to-casualty ratio at the towers was inverted compared to most mass-casualty incidents. Most victims either escaped on their own or did not survive. The triage challenge wasn’t a massive sea of injured survivors needing sorting. It was locating those who could still be reached, quickly assessing them, and moving them before secondary collapses occurred. That is precisely the scenario START was engineered for.

What Is the START Triage System and Why Was It Built?

START was developed in 1983 by Hoag Hospital and the Newport Beach Fire Department in California. The system was updated in 1994 to reflect real-world deployment experience. It exists because standard medical assessment takes too long when dozens or hundreds of patients need attention at once. The goal isn’t perfect diagnosis. It’s rapid prioritization: who needs help immediately, who can wait, who can walk, and who is beyond immediate help with the resources available.

The system uses the RPM mnemonic: Respirations, Perfusion, and Mental status. Each assessment takes under 60 seconds. Responders categorize victims into four color-coded groups: red (immediate), yellow (delayed), green (minor/walking wounded), and black (deceased or expectant). The color tags do the communicating so responders don’t have to.

“Mass casualty incidents demand that responders perform rapid assessments and quickly classify patients according to the urgency of their injuries, so that limited resources can be directed where they will do the most good.”

— National Institutes of Health

The START system has been deployed at some of the most demanding incidents in modern American history, including the 1993 World Trade Center bombing, the 1995 Oklahoma City bombing, and the September 11 attacks. Those deployments, spanning nearly a decade before 9/11, validated the core methodology under extreme real-world conditions.

What Did the Scale of 9/11 Demand from the START Protocol?

The September 11 attacks weren’t a single mass-casualty incident. They were simultaneous, compound, and evolving. Tower 1 was struck at 8:46 a.m. Tower 2 at 9:03 a.m. Both collapsed within two hours. Each collapse changed the incident profile entirely: victims in the collapse zone, rescue workers caught in debris, survivors emerging from the rubble over subsequent hours.

Responders using START faced conditions that pushed the protocol to its edges. Here’s what the triage environment looked like:

• Massive initial survivor flow from lower floors in the first 90 minutes before collapse
• Hundreds of walking-wounded (green tag) self-presenting at staging areas blocks away
• Limited ability to physically access red-tag victims inside the towers
• Secondary hazards (jet fuel fires, structural instability) affecting triage zone safety
• Dust inhalation and smoke complicating respiratory assessment
• Responders themselves becoming casualties during and after collapses
• Communication breakdowns between FDNY, NYPD, and EMS units

START’s strength in this environment was its simplicity. In multi-agency responses where communication breaks down, a shared protocol means two responders from different departments can work the same victim without conferring. The RPM assessment is the same whether you’re FDNY or NYPD EMS. That shared language matters enormously when normal command structures are overwhelmed.

What Triage Challenges Are Unique to Terrorist Attacks Versus Natural Disasters?

Natural disasters, building fires, and industrial accidents create mass-casualty events. Terrorist attacks create them deliberately, with secondary devices, structural traps, and ongoing threat environments. That distinction changes how triage must operate.

At 9/11, responders had to factor in:

• Unknown threat status (a third plane was still unaccounted for in the first hour)
• Potential for secondary structural collapse during rescue operations
• No clearly defined safe perimeter in the first 90 minutes
• Psychological trauma affecting both victims and responders equally
• Media and bystander interference with staging areas

In these conditions, the black-tag decision becomes harder. Declaring a victim expectant when structural conditions might change, when resources might shift, requires discipline. START gives responders the framework to make that call without agonizing over it. That reduces decision fatigue under pressure, which is the system’s core value proposition in terrorist-attack scenarios.

What Did 9/11 Teach Us About Pre-Incident Preparedness?

The after-action analyses of September 11 consistently pointed to the same gap: inter-agency coordination. Individual units were well-trained. The system connecting those units broke down under load. As extensively documented in post-incident reporting by The New York Times, radio communication failures and unclear command hierarchies cost critical minutes during the evacuation of Tower 2. Triage protocols work best when command structures work. Pre-incident training has to address both.

“Effective emergency response in mass-casualty incidents requires that all responding agencies practice together before the incident, not just individually within their own organizations.”

— Centers for Disease Control and Prevention

This is where START’s training infrastructure carries weight beyond the algorithm itself. The system includes structured drill plans, instructor manuals, and scenario-based exercises designed to build muscle memory across multi-agency teams. After initial training, responders can triage each victim in 60 seconds or less. That speed only holds under pressure if the team has practiced together, repeatedly, in conditions that simulate the chaos of a real incident.

How Can Emergency Teams Apply 9/11 Lessons in Training Today?

You don’t need to wait for a mass-casualty event to find out whether your team is ready. The 9/11 after-action record is a training syllabus. Here’s what it points to:

1. Train across agencies, not just within them. Shared protocols only work if every responding department uses the same one.
2. Practice communication failures. Build drills where radio contact is simulated as lost. Your team should know how to triage without it.
3. Define triage zones in advance for your highest-risk locations: stadiums, transit hubs, high-rise buildings, schools.
4. Designate green-tag staging areas well outside the hot zone so walking wounded don’t flood treatment areas.
5. Run full-scale exercises that include bystanders and media simulation, because those variables compound incident complexity significantly.
6. Review black-tag criteria annually. The hardest calls are the ones teams avoid rehearsing.

The START triage training materials include instructor manuals, lesson plans, drill plans, and quality assurance tools designed specifically to support this kind of multi-session, scenario-based preparation. Departments that ran those drills before 9/11 were measurably more effective in those first critical hours than those who hadn’t.

The September 11 attacks remain the defining mass-casualty event of modern American emergency response. Not because it was the largest in absolute terms, but because it happened in the most-watched, most-resourced city in the country, with cameras running, and the gaps were still catastrophic. Every first responder, emergency coordinator, and disaster preparedness team owes it to the people they protect to study that day honestly, train against its lessons relentlessly, and build the kind of muscle memory that runs when the brain is overwhelmed. A system that is easy to learn, easy to remember, and easy to use isn’t a luxury. On September 11, it was the difference between organized response and paralysis. Make sure your team has that system before they ever need it.