The flames broke out around 3 a.m. at the Deliverance Tabernacle Church on Sutter Avenue in South Ozone Park.
The fire started in the basement of the church and spread to the first floor. Fire Marshals say the cause of the fire was due to electrical wiring.
It took about an hour for firefighters to get the upper hand after they had a little trouble with frozen hydrants when they arrived.
"The church was sealed up tight, and we had a floor collapse on the first floor," FDNY Chief Gerry Quinn said. "So it was pretty dangerous at the time. Due to the conditions, we called a second alarm because of a couple of hydrant problems with the ice and the long stretches that the firefighters had to make."
The four injuries are reportedly minor, caused mostly by slipping on ice.
No one was inside the church, which has a congregation of about 80 people.