It happened at the Black River Grove Baptist Church on North Broad Street East.
Authorities said they did a thorough search of the building but did not find anyone inside.
Firefighters got word of the collapse after someone driving by saw it and went to the firehouse to tell them.
Lucy McClean, is the church treasurer. At 85 years old, she's the oldest member of the church. She went by to survey the damage.
"It means a lot that we can help people and people come and they get saved," McClean said. "That's the main importance.
This woman heard a large crash this afternoon and finally realized it was the church next door whose roof had come down. We’re gathering more details and we will have an update on Tv at 6 #ABC11 pic.twitter.com/puvgh2SBuX— Josh Chapin (@JoshChapinABC11) May 2, 2018
"We were at a funeral in Dunn when we got home, my daughter called and told me what happened," she added. "I'm so thankful because we have services Sunday. It could've happened Sunday, but it didn't. Lord knows the best - He knows what he's doing."
Thomas Hockaday, who has worshipped at the church for five years, was teaching Bible study on Tuesday night.
"What we're happy about is that no one was inside the sanctuary," Hockaday said. "All of us were in that area last night. Now if we had come into the sanctuary for some reason, and it collapsed then, that would've been bad - it would've been tragic."
Harnett County building inspectors have condemned the portion of the church that collapsed.
Firefighters were not able to get far enough into the building, which dates to the 1920s, to see what could be saved.
"We can get another building and we're going to rebuild," Hockaday said. "This is not the end. This is just a new beginning for us."