But his determination to participate hasn't.
"As long as I'm breathing, I'll be here," Acquaviva, 81, said Friday as he arrived to pay tribute to his late son, Paul.
More than 1,000 victims' relatives, survivors and recovery workers marked the 14th anniversary at ground zero with grief, gratitude and appeals to keep the toll front of mind as years pass. "It's a hard day. But it's an important day. I'll come every year that I can," recovery worker Robert Matticola said.