Joseph Zadroga — a fierce advocate for first responders who suffered illness after the 9/11 attacks — died in a freak accident yesterday when he was struck by an elderly driver who mistakenly hit the gas in a New Jersey parking lot.

Mr. Zadroga — the father of late 9/11 first responder James Zadroga — had just visited his wife at the hospital when he was struck in the parking lot by 82-year-old driver James McNeal at around 2 p.m.

Joseph Zadroga, 76, of Little Egg Harbor, has been credited with spearheading the Zadroga Act for 9/11 families which helped deliver much-needed funds to the families of first responders.

He was standing beside his parked Hyundai Tucson when McNeal tried to park his 2021 Nissan SUV at about 2 p.m. and hit the gas instead of the brake. Zadroga was struck by the McNeal’s SUV and pinned underneath.

Zadroga’s son, James, was a veteran NYPD cop who died in 2006 of a respiratory illness he developed after responding to the 9/11 attacks in Lower Manhattan.

His death — at just 34 years old — was attributed to the presence of a variety of particles in his lungs. The Zadroga family became famous after lending their name to a 2011 law that provided health benefits and compensation to others who fell ill after responding to the World Trade Center site.

After his son’s death, Joseph Zadroga and other activists pushed hard to extend the law for 25 years past its initial 2016 expiration date. “I just want everybody out there, the victims who got sick, to have the health care that they deserve, because Jimmy didn’t get it,” Zadroga said at a 2014 rally near Ground Zero, and he wept when he remembered that his son could barely walk up the stairs in the end.

Former North Arlington Police Chief, who retired years ago, Joseph Zadroga took up the cause of getting help for first responders after problems his son encountered getting medical help and acknowledgement from city officials that his son’s illness was 9/11 related.