The Tulsa Fire Department said it is investigating a church fire as an arson case.

As Tulsa firefighters rushed to the Chapel of Restoration near 21st and 145th East Avenue Thursday night, they discovered one of the buildings on fire.

Even though the Chapel of Restoration lost its drums, a keyboard and microphones in the fire, it still plans to have services on Sunday, while firefighters work to figure out who started the fire.

"When we first arrived, there was pretty heavy flames coming from the roof. The crews made an initial fire attack, but it was very brief as they noticed that the roof was sagging, one of the walls was bulging,” Andy Little with the Tulsa Fire Department said.

Osage Drone 6 shows the roof of the Fellowship Wing collapsed.

Inside, the children's area has damage, and so does the space where the Spanish speaking congregation meets. Church leaders said someone left a message on the wall outside.

"I'm sure that that means separation of church from the states. But we have nothing to do with the state. This is a church of God,” Minister Akeem Odutayo said.

Odutayo is trying to make sense of what someone wrote.

"We don't understand that. And it says, ‘I want to go home.’ So I don't know. Does that say ‘I want to go home, I wanted to go home?’ Because this is an immigrant church. So it's a little bit concerning," he said.

Since the fire was contained to the fellowship hall, and the building with the main worship auditorium is fine, Odutayo said it will still hold services on Sunday morning.

"We're gonna keep on moving. The church is gonna keep on marching on,” he said.

The church said thankfully it does have insurance and plans to rebuild.