FDNY Commissioner Sal Cassano, along with hundreds of firefighters, were in attendance.
Lieutenant Nappi died of a heart attack after he became overheated while battling a warehouse fire in Brooklyn on Monday.
Nappi grew up in Farmingville, where he served as a state parole officer and case worker.
The 47-year-old had a very distinguished career and was one of the many who responded to the World Trade Center on 9/11.
He lived in Farmingville with his wife and their two children, a 12-year-old daughter and an 11-year-old son. But often he could be found in nearby Yaphank, at the Suffolk County Fire Academy, where he served as a field instructor.
"I come in here, and he'd be sitting there, and I'd say 'Rich, you're not scheduled for tonight,'" Suffolk Fire Academy Chief Bob Hopkins said. "'Somebody's bound to call and cancel, so I'm here,' he says. 'I'm available.'"
Nappi is the first city firefighter to die in the line of duty since 2009.
A funeral mass will be held Saturday, April 21 at 10:30 a.m. at St. Elizabeth Ann Seton Roman Catholic Church, followed by burial at Holy Sepulchre Cemetery in Coram.
At the request of the officers and members of Engine 237, a scholarship fund has been established by the FDNY Foundation for Nappi's children.
Lieutenant Richard A. Nappi Children's Education Fund
9 Metrotech Center
Brooklyn, NY, 11201
All Donations are tax-deductible, and 100 percent of the donation will be given to the Lieutenant Richard A. Nappi Children's Education Fund.
Get Eyewitness News Delivered