“For every Serb, there is a lot of sadness today,” said Mr. Zelenovic, who added that, within days of arriving in New York from Serbia in 1972, he began attending Mass at St. Sava.

Image Charred remains of the church. The wooden interior may have fed the flames. Credit... Kirsten Luce for The New York Times

The church had been a spiritual destination for Serbs living in the region, including many from Queens neighborhoods like Glendale, Maspeth and Ridgewood.

It was a journey that required Mirjana Jovanovic, of Glendale, to take three trains and a bus to attend the Easter service, all while carrying the dozen colored eggs she had made.

Ms. Jovanovic said she began attending services there almost immediately after immigrating to New York from Serbia in 1986. She was married in the church in 2002, she said on Monday after talking her way past police lines so she could take snapshots of the building, “just to remember.”

Besides news reports, word of the fire spread by word of mouth and over the church’s website, which alerted parishioners with a simple headline: “Our Church Has Burned Down.”

Flames first began appearing out of the top edges of the front double doors, and within minutes, the circular stained-glass window higher up on the facade shattered, and “a big tongue of fire came jumping out,” said Herman Tulp, a Dutch tourist staying across the street at a hotel.

“It was apocalyptic,” he said.

Firefighters responded to the blaze around 7 p.m., which grew and required roughly 170 department personnel to curb, a Fire Department spokesman said.