Thirty-two people were added to the FDNY’s memorial wall commemorating members of the department who died from 9/11-related illnesses on Thursday, nearly double the number of people added last year.

The FDNY’s World Trade Center Memorial Wall, created in 2011, now features 159 names of fallen members who died from illnesses related to their work at Ground Zero, including firefighters, paramedics and fire marshals. Last year, 17 names were added to the wall.

This year, the names added included a father and son who passed away within months of each other and Ray Pfeifer, who fought to extend the James L. Zadroga 9/11 Health & Compensation Act, which provides health care for first responders with 9/11-related illnesses, and lost his yearslong battle with cancer in May.

“We don’t know when this loss will stop. No one knows,” FDNY Commissioner Daniel Nigro said during the ceremony on Thursday. “We only know that far too many more of our members are sick and we know the number who lose their lives because of September 11 continue to grow year after year.”

Family members gathered inside the FDNY’s Brooklyn headquarters on Thursday afternoon, solemnly placing flowers by the memorial wall as their loved ones’ names were called out.

Two of the people memorialized were Lt. Raymond Alexander, who battled cancer for 13 years and died late last year, and his son Robert Alexander. The latter was an NYPD officer on 9/11, joined the FDNY as a firefighter in 2002 and spent 10 years with the marine unit.

“It’s been kind of hell,” said Ray Alexander, Raymond’s son and Robert’s brother, about the last year. “It took six months for me to figure out my dad’s gone, the permanence of that, and right as that happened my brother lost his ability to walk and speak ... it was incredibly painful to watch.”

His mother, Ginger Alexander, said it’s important that people realize, “it’s still happening, people are still dying.” Alexander said she still hasn’t come to terms with the deaths of her husband and son.

“All New Yorkers have been terrific, very supportive,” she added. “During 9/11 and after 9/11 people couldn’t do enough.”

Nigro said there are still more than 1,000 FDNY members, both active and retired, who are “seriously ill with World Trade Center illness.” Nigro added that “there is no doubt” the number of those who will die from 9/11-related illnesses will increase, “and these sad days will continue.”