People touch the stones in the Memorial Glade dedicated to those who died of 9/11 related illnesses, after opening ceremonies.

A visitor looks at the reflecting pool adjacent to the 9/11 Memorial Glade before opening ceremonies.

Maureen Fritz holding a photo of her brother FDNY firefighter Billy Gormley of Ladder 174, who died on June 14, 2015, from an illness related to his response to the World Trade Center on 9/11.

They couldn’t be bothered.

Gov. Andrew Cuomo and Mayor Bill de Blasio blew off a solemn dedication ceremony Thursday for a memorial to those who died from toxic exposure to Ground Zero — and got blasted by first responders and their families.

“They should have been here and it’s unacceptable that they’re not,” said Maureen Fritz, who attended the 10:30 a.m. event in honor of her brother, firefighter William Gormley, who died in 2016 of 9/11-related illness.

“They ought to be ashamed of themselves . . . They should not be reelected at all because that’s not how you treat your citizens, your first responders.”

While he had no time to observe the opening of the 9/11 Memorial Glade, blocks from City Hall, de Blasio found time to schlep from Gracie Mansion to Brooklyn for his morning coffee and regular workout in Park Slope Thursday morning.

Cuomo, meanwhile, had been expected to deliver a speech at the dedication, but canceled it at the last minute, organizers said. Instead, he sent the counsel to the governor, Alphonso David, while he hunkered down in Albany.

Celebrities and dignitaries, including former Mayor Mike Bloomberg, former “Daily Show” host Jon Stewart, who has advocated for 9/11 responders, and several local Congress members, did show up.

Kate Monaghan Connolly, spokeswoman for the 9/11 Memorial & Museum, said both de Blasio and Cuomo were invited. Another 9/11 Memorial & Museum spokeswoman, Olivia Egger, said that the governor was expected to attend but canceled at the last minute citing a scheduling conflict.

Museum officials wouldn’t comment on the snubs.

But retired FDNY Officer Rob Serra, who responded to Ground Zero on his first day of work, was not willing to keep quiet about the glaring no-shows.

“I think they should have been there, but one’s running a campaign and I don’t know where the other one is,” said Serra, who is now in a wheelchair from related illnesses including peripheral neuropathy that causes numbness in his limbs

Thursday morning, DeBlasio — who always seems to find time for his Quixotic presidential run — was spotted at his usual coffee shop, Colson Patisserie, in Brooklyn at about 7:30 a.m. and his security detail was spotted at his favorite gym, the Park Slope Y, starting at about 8:30 a.m. and remained until about 10 a.m.

A spokeswoman said he was attending an “internal meeting” at Gracie Mansion afterwards, coinciding with the half-hour ceremony — without providing any other details.

A Cuomo spokeswoman said the governor never planned to attend the dedication, but insisted he supported The Glade. Richard Azzopardi said his boss “was always going to be in Albany dealing with end of session issues.”

Lt. Gov. Kathy Hochul also failed to attend, and instead attended a capital region women’s luncheon.

Michelle Holfester, whose husband Det. William Holfester died in 2008 at 43 from cancer related to Ground Zero, wasn’t buying the excuses.

“They should have been here, that’s the bottom line,” she said. “We’re here where are they? They’ve seen through the years what’s been going on the suffering with the men and women that lost their lives post 9/11 … It’s not a good picture. It doesn’t look good you know.”

The Glade is located at Liberty and West streets. It will include a path lined with six stone monoliths pointing toward the sky that “are worn, but not beaten, symbolizing strength and determination through adversity,” according to the museum.

The Canadian granite slabs, weighing as much as 17.5 tons, will incorporate steel fragments from the World Trade Center.

The plan was done by Michael Arad and Peter Walker who designed the 9/11 memorial, and it comes with a about $5 million price tag.

The state chipped in half a million dollars, and Bloomberg Philanthropies, the Building Trades Union and others gave generous donations.

Stewart, a 9/11 museum board member, helped lead the fundraising effort. The memorial received no money from the city.

Bloomberg, who is chairman of the memorial museum board, said the Glade helps fulfill a duty to honor the memory of those who died.

“In the years since 9/11 thousands of people have become ill or died from causes related to the attacks,” he said. “That group includes many people who participated in rescue or recovery. it also includes people with homes and workplaces in the surrounding area who would not allow terrorists to force them to abandon their communities.”