One of the stories yet to be told about the Boston bombing is the tremendous work done by the Boston Emergency Medical Services team. If one considers the nature of the event, it as astonishing that only three people died. It's easy to credit the poor quality of the explosive devices, the timing of the attack, or even luck with the low number of fatalities. But luck had nothing to do with it: Boston EMS was ready.
As do most large cities, Boston takes large civic events seriously and does considerable pre-planning. The Boston Marathon is certainly THE signature event for Boston and was no exception. What is different about the planning in Boston is that Boston EMS, as a matter of policy, treats the Boston Marathon and other large events as a mass casualty event. That means that all the equipment, facilities and staff required to respond to a mass casualty event were fully deployed at the time of the attack. Note that this does not mean they were "on alert" or "on standby" but were actually in the field with medical caches available, ambulances staged, and staff on scene.
The results speak for themselves. According to Boston EMS Chief James Hooley, his team was able to clear the scene of victims in 18 minutes. A medical tent for triage was already set up. Ambulances were available to transport the injured without the need for an uncoordinated evacuation by civilian vehicles. A well-practiced communications system with local hospitals ensured that no one hospital was overloaded. Mutual aid partners were in constant contact with the on-scene management team.
There is no question that such a heavy deployment of resources is expensive and can't be done for every event. However, the larger issue is Boston EMS commitment to training for mass casualty events. It is a task they take seriously. The deployment of resources would not have been so effective without a trained and experienced team of professionals to use them.
The Boston experience highlights the importance of both training and planning for mass casualty events. A small jurisdiction may not be able to pre-stage resources as Boston does but it can certainly plan for how it would handle a mass casualty event. It's all in the commitment.