A fire at Barron hall in Glengormley, County Antrim, in the early hours of Friday morning is being treated as malicious.
The blaze at the cross-community venue on the Antrim Road was reported to police at about 0030 BST.
The Fire and Rescue Service extinguished the flames but the hall was destroyed.
The PSNI believe the oil supply to the premises may have been tampered with and the roof deliberately set alight.
The hall is the headquarters of the Newtownabbey Community Forum.
The forum co-ordinator Kathy Wolf said she was "totally devastated" by what had happened.
"This is a hall that we built up over the past two years to make it a shared space, not a neutral space but a shared space.
"We've built it up so that it's a place that everyone within the borough and further afield can use," she said.
"We have events on nearly every single day.
"We have youth groups, Irish dancing, Citizens Advice, Newtownabbey Senior Citizens Forum.
She added: "To get a phone call last night and arrive and see the fire tenders and police there and the smoke coming up through what was left of the roof has just been heartbreaking."
On Friday, Police Chief Inspector Paula Hilman condemned those responsible.
She said "This venue was a welcoming space for all sides of our community and thanks to mindless vandals it has been completely destroyed."
SDLP Newtownabbey councillor Noreen McClelland said it was a "despicable" attack on the local community.
"Barron hall is a central hub for the people of Glengormley and this attack has threatened the good work that is being done by those associated with the hall.
"I strongly condemn this attack which could have killed or seriously injured someone."