Dennis Patrick McCarthy
Incident
Location: New York Incident Date: Tuesday, September 11, 2001 Weapon: Aircraft; Passenger jet Offender: 19 suicide attackers
Special Agent Dennis McCarthy died as the result of cancer contracted due to his exposure to toxic substances following the 9/11 Terrorist Attacks at the World Trade Center in New York City, New York.
Agent McCarthy responded to help secure the site of the destroyed U.S. Custom House at the World Trade Center site in the immediate aftermath of the attacks. He remained at the scene to assist with search and recovery efforts.
Special Agent McCarthy had served with Homeland Security Investigations and the former United States Customs Service for over 31 years. Special Agent McCarthy's brother was also a DEA agent who was killed in combat during the Gulf War while activated with the U.S. Marine Corps Reserve.
September 11, 2001 - The Years After
Special Agent Dennis Patrick McCarthy was assigned to the search and recovery at the World Trade Center site after September 11, 2001. He was 48 years old that fall.
He died on October 27, 2018 - 17 years and 1 month later - of an illness contracted there. He was 65.
He is one of 599 officers honored here, and one of 7 at United States Department of Homeland Security - Immigration and Customs Enforcement - Homeland Security Investigations.
The most recent of these deaths was October 24, 2025.
Officers who worked the search, rescue, and recovery at the World Trade Center site breathed contaminated air for weeks and months afterward. Many developed cancers and respiratory disease, and they have gone on dying of it ever since.
Seventy-two officers were killed on the morning itself. Hundreds more have died in the years that followed. They are honored here together, because the same attack killed them all. With some it simply took longer.
In Our Keeping
- Permanent identifier
BO-US-FED-FB31985A- Stewardship
- Maintained by NeuraWeb Global Inc.
- Added to badge.nw
- April 2, 2026
- Last updated
- July 23, 2026
Honored here by 1 sentinel - 1 tribute.
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Tributes
You walked into it and it took years to finish the job.
Special Agent McCarthy gave the United States Department of Homeland Security 31 years.
Thank you for your service. Gone but never to be forgotten.
Rest easy, Special Agent McCarthy.
— S. Vincent Anthony, U.S. Army 1985-1993
Agency
Service Record
Incident Details
Special Agent Dennis Patrick McCarthy is one of 2,974 officers lost to illness connected to their service across the full record of this memorial — 9.1% of all 32,508 officers honored here.
In DC, 137 of 1,419 officers were lost to illness connected to their service — 9.7% of this state's fallen. That is 0.6 percentage points above the national rate of 9.1%.
At United States Department of Homeland Security - Immigration and Customs Enforcement - Homeland Security Investigations, 8 of 10 officers on record were lost to illness connected to their service — 80% of this agency's fallen.
National Cause Distribution
How Illness compares to all causes of officer death in the memorial record. Dennis Patrick McCarthy's cause is highlighted.
How Dennis Patrick McCarthy Compares
Offender Outcome
19 suicide attackers
When Illness Deaths Occur
Monthly distribution of Illness deaths across the full memorial record. Dennis Patrick McCarthy is highlighted in Oct.
Incident Location
Others Who Wore This Badge
9 officers from United States Department of Homeland Security - Immigration and Customs Enforcement - Homeland Security Investigations are honored on badge.nw.








