A deadly fire that broke out at a community center before a Portuguese religious feast started when candles ignited crepe paper decorations in the heavily adorned hall, fire officials confirmed Thursday.

Four people were killed and at least 12 were injured Wednesday evening in this working class coastal city, which has an active and deep-rooted Portuguese community, authorities said.

"What makes this an incredible tragedy is these hard-working Fall River families were gathering to celebrate their lives, their culture, their spirit, their faith," Mayor Ed Lambert said at a news conference Thursday.

"They didn't have a chance," Bristol County District Attorney Paul F. Walsh Jr. said.

Thirty people were on the ground floor of the three-story building when the flames began, Lambert said. The building has apartments on the two floors above the community hall.

Fire Chief David Thiboutot said there was a delay in calling for help as people inside the hall tried to extinguish the flames themselves. Others were trying to go back into the building as firefighters arrived to find injured people outside and reports of people trapped, he said. There were no sprinklers.

Nelson Raposo, 31, who lives in a second-floor apartment, said an explosion rattled his floor before sunset.

"We just heard the big bang and felt the pressure," said Raposo. "I opened the front door, but all I saw was smoke."

As the smoke rose in the hallway, Raposo led his family out a window and onto the roof. The family had to climb down through a tent that had been set up in the back parking lot for the festival.

Another neighbor, David Martin, 31, said he saw a man fleeing the three-story structure with his shirt on fire. The man screamed that his wife was trapped, and he tried to run back inside before he was stopped by firefighters, Martin said.

Police blocked off streets surrounding the building. Neighbors gathered at the yellow caution tape, some whispering in Portuguese and weeping.

At least 10 community members and two firefighters were taken to hospitals with burns.

Fall River is 20 miles (30 kilometers) southeast of Providence, Rhode Island. Almost half of its 92,000 residents claim Portuguese heritage, according to the 2000 Census.