Thousands gathered to pay their final respects to Wirtz at St. Barnabas Church.
His funeral comes more than a week after a fire ripped through a home in North Haven.
It happened the day after Christmas.
The medical examiner's confirmed the 46-year-old died of cardiovascular disease after he collapsed at the scene.
Wirtz was a member of the fire department for 22 years.
MORE NEWS | MTA worker attacked, suspect pulled from under subway car in Chelsea
Suspect in MTA worker attack pulled from under subway car
----------
* More Connecticut news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube