A chunk of steel cut away by iron workers at Ground Zero. A fragment from one of the airliners that crashed into the Twin Towers. A small piece from one of the downed buildings where nearly 3,000 people perished almost a decade ago.

Those and other artifacts, symbolizing grief, tragedy and heroism, were put on display Wednesday during a ceremony in Rockville Centre, four days before the country commemorates the 10th anniversary of 9/11.

Gov. Andrew M. Cuomo, who attended the event, said the exhibit should both honor the victims and first responders, and also serve as a teaching tool for the next generation of New Yorkers, many too young to remember the attacks.

"On 9/11 you have the best and the worst," Cuomo said. "You have evil and you have hope. You have terror and you have heroism. And both of those lessons are there and both of those lessons have to be taught to the next generation."

The "New York Remembers" exhibit at the Rockville Centre Recreation Center is one of 30 across the state and the only one in Nassau County. A Suffolk County exhibit is open at Stony Brook University's Charles B. Wang Center.

More than 2,000 mementos, many of which have never been seen by the public, were donated by the New York State Museum and the National September 11 Memorial to sites across the state.

The Rockville Centre exhibit includes artifacts large and small -- from the door of a shattered Port Authority police vehicle to a computer circuit board recovered from the rubble.

advertisement | advertise on newsday

The display includes a timeline of the attacks and short vignettes of most of the 48 Rockville Centre residents who died at Ground Zero.

"Rockville Centre paid a terrible price on September 11, 2011," said Mayor Francis Murray. "Our community changed forever. We never recover. We learn to live with it. And only pieces of us heal."

Among the victims were Bernie O'Brien's son Tim and son-in-law Steve Tighe, who were working at Cantor Fitzgerald at the time of the attacks. The Rockville Centre natives left behind seven children.

"They were the rocks of our family," O'Brien said. "And they will always remain as such."

The exhibit will be open through the end of September.