A funeral mass for Capt. Christopher Leach got underway at noon at St. Elizabeth's Catholic Church.
Leach's body was brought to St. Elizabeth's in a flag-draped coffin carried on the back of a fire truck.
It was part of long procession of first responders who made their way to the church Friday morning.
Bagpipes could be heard as mourners waited under a cloudy sky.
"I think just by the turnout here in Wilmington that you're seeing that he was a respected and honored man and he died doing what he loved to do," said Kurt Hoffstein of Wilmington.
"We don't care, day or night, what time of year, cold or hot, we go in and do our job. We're firefighters, that's our job. We don't look at the circumstances of what is going to happen after the fire. We're there to do a job and put that fire out," said Timothy Taggert of the Wilmington Fire Department.
It was an emotional Mass at Leach's parish.
"We are reminded in Ecclesiastes that there are times for everything, and we cannot know God's plan completely," said Bishop W. Francis Malooly. "Certainly, in this place, we don't know what God's plan is."
The farewell for Capt. Leach followed a viewing for Lt. Jerry Fickes on Thursday evening, who also perished in the rowhouse blaze on the morning of Saturday, Sept. 24.
Earlier Thursday, investigators said the fire was intentionally set.
Charged is 27-year-old Beatriz Fana-Ruiz, a resident of the house who allegedly confessed she started the fire in anger and then fled.
Firefighters arrived on the scene early Saturday morning and had received reports that people were trapped.
They rushed in and the floor beneath them collapsed.
A joint memorial service honoring both firefighters will be held at 1 p.m. Saturday at the Chase Center on the Riverfront, located at 815 Justison St. in Wilmington.
The service will be open to the public. Doors will open at 12 p.m.