Authorities say the candles were placed in a cardboard box by a caretaker.
Fire engulfed the Serbian Orthodox Cathedral of Saint Sava on the holiest day on the Orthodox calendar.
The building, built in the 1850's, spans an entire block from West 25th to 26th Streets.
It took firefighters three hours to extinguish the blaze, which completely destroyed the church's roof.
Investigators are now able to go through the ashes from the fire and say that so far there are no indications of anything suspicious.
Five firefighters suffered minor injuries.