Dennis was born to Agnes and Peter Gilhooly on June 8, 1951, and grew up in the Fordham Road area of the Bronx.  After graduating from Fordham University in 1974, he began a decades-long career of public service to the people of New York. 

Dennis served as a New York State Trooper in Troop K in Dutchess County and Troop L in Long Island.  Then, in 1981, he followed in the footsteps of his father, Peter Gilhooly, and joined the Fire Department of New York (FDNY).  Dennis began fighting fires in the busy Engine 75 of the Bronx.  During that time, he suffered burns and spent time recovering in the New York City Burn Center.  He was later promoted to Fire Marshal and worked throughout the Bronx as an arson investigator.  In 1991 he was promoted to Lieutenant and led the firefighters of Engine 67 in Washington Heights.  In the aftermath of the terrorist attacks on September 11, 2001, Dennis was promoted to Captain and worked in the long recovery effort at the World Trade Center.  Dennis then served as Police-Fire Liaison at Police Headquarters before retiring from the FDNY in 2004.

In addition to his full-time public service, Dennis contributed to the larger community in many other ways.  He served in the New York Air National Guard for 22 years, retiring as a Master Sergeant.  He also joined the Stanford Fire Company in 1987 serving as a firefighter and 2nd Lieutenant.  He was currently serving as a Commissioner for his tenth year.

While he was a hero to many throughout his career, he was a hero to his children from day one.  He made it a priority to be present in the lives of Luke, Ian and Tara.  He supported them throughout their various academic and personal achievements and was sure to be there for every sports game and awards ceremony, always with his video camera in tow.  

He was known throughout the community for his kindness and dry wit.  He was always there to ‘patiently’ support the love of his life, his wife of 45 years, Laura Gilhooly, as she taught at Cold Spring Elementary and spearheaded various volunteer projects.  Laura was by his side every step of the way in his long battle with cancer.  Their strength in the face of adversity and devotion to each other is one for the books.

Dennis left the neighborhoods of the Bronx to live a quiet life in the country.  He loved the beautiful land of Dutchess County and lived for deer hunting season every year with his brothers and friends.  He was diagnosed in 2005 with cancer related to his service at the World Trade Center, and battled fiercely for the last three years before passing away peacefully with his family at his side. 

Dennis is survived by his wife Laura, his children, Luke, Ian and Tara and their spouses, Gabrielle, Amanda and Garvey.  Grandpa/PopPop/Babu found absolute joy in his grandchildren, Maya, Peter, Penelope, Knox, Noah, and Ayla.  He will be greatly missed by his siblings Jeanne, Pete, Nancy, Dean, and Steven, and their spouses, John, Tim, Mary, Kari and Amy and his 32 nieces and nephews.  Dennis’ life was made richer by his longtime friends and those he met along the road of a life well-lived.