This article is a list of the emergency and first responder agencies that responded to the September 11 attacks against the United States, on September 11, 2001.
These agencies responded during and after the attack and were part of the search-and-rescue, security, firefighting, clean-up, investigation, evacuation, support and traffic control on September 11.
World Trade Center, New York City, September 11.
This list is a list of emergency services, first responder agencies and organisations that responded to the terrorist attack at the original World Trade Center in New York City.
Law enforcement agencies.
At least 10 law enforcement agencies responded to the terrorist attacks at the WTC. 
There were many losses, from these agencies:
This is a list of the law enforcement agencies (Federal, State and Local) that responded on 9/11.
Emergency Medical Services (EMS).
Many different emergency medical services responded to the WTC. Some of these agencies are listed below:
Bensonhurst volunteer ambulance service, sent 2 ambulances and 2 p.o.v.
Military and Federal Government agencies.
(U.S Air Force Auxiliary.) The Civil Air Patrol was deployed to help secure the air space around lower Manhattan according the Dept of Homeland Security.
Pentagon, Arlington, September 11.
This list is a list of emergency services, first responder agencies and organizations that responded to the crash of American Airlines Flight 77 at The Pentagon in Arlington County, Virginia, just outside of Washington, D.C.
Shanksville, Pennsylvania, September 11.
This list is a list of emergency services, first responder agencies and organizations that responded to the crash site of the failed hijacking of United Flight 93 in Stonycreek Township, Somerset County, Pennsylvania, just outside Shanksville, Pennsylvania.
Law enforcement agencies.
70 agencies responded to the crash at Shanksville.
References.
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