He came again Thursday to participate in the state's official service marking the 10th anniversary of the terrorist attacks.
Spagnoletti, of Waterbury, said he wanted not only to honor the memory of his son, who died at age 32, but also to be with others who suffered a similar loss.
"It's easier to communicate with them," he said. "I hope the rest of the country stands with us, too."
In his speech to the crowd, Gov. Dannel P. Malloy spoke directly to the family members.
"Your state, your fellow citizens here in Connecticut, your fellow citizens here in the United States and your fellow citizens of good will in this world once again express their condolences and love to each of you," he said. "Your sacrifice will never be forgotten."
Of the 3,000 victims, 152 people with ties to Connecticut were killed in the attacks on the twin towers in sight of the state park that abuts Long Island Sound and was dedicated as a 9/11 memorial site in 2002.
The services included the reading of the names of Connecticut's victims and the dedication of a metal sculpture of flowers. Another memorial at the park features stones etched with the victims' names.
Organizers of the service also displayed memorabilia such as then-Gov. John G. Rowland's proclamation declaring Sept. 11, 2001, a day of remembrance and photos of other 9/11 memorials in Connecticut.
Spagnoletti's sister, Mary Mascolo of Waterbury, joined her family at the service. Her nephew's death was "tough at the beginning," she said.
"It never goes away," Mascolo said. "He just started his life. We loved Greg."