Investigators are trying to figure out what sparked a massive fire that destroyed an historic Manhattan church Sunday.

Flames broke out at the Serbian Orthodox Cathedral of Saint Sava on West 25th Street near Broadway just before 7 p.m.

Firefighters got the flames under control about three hours later.

Parishioners celebrated Serbian Orthodox Easter with a church service and lunch just hours before the fire. 

"This cathedral serves as the Serbian population or our metropolitan area, very large population. So it's a very sad day for them. Somehow they'll get through it," said FDNY Commissioner Daniel Nigro.

Fire crews continued to pour water on the building Monday morning, and 25th and 26th streets between Broadway and 6th Avenue remained closed to traffic.

The city Department of Buildings says there is no immediate danger of collapse but will be monitoring the site for loose debris that could still fall.

"The hope is that it is salvageable in some way. This is a historic, gorgeous, landmark building and the Department of Buildings was going in this morning to make an assessment on the structure and the stability of the structure. There's been no collapse yet, which is good news, but the next few days are going to tell us what the real state of the church is moving forward," said City Councilman Corey Johnson.

The church was built in the 1850s, and was designated a landmark in 1968.

Four firefighters and the church's caretaker suffered minor injuries.