SANTA MARIA, Brazil (AP) -- A fast-moving fire roared through a crowded, windowless nightclub in southern Brazil early Sunday, filling the air in seconds with flames and a thick, toxic smoke that killed more than 230 panicked partygoers, many of whom were caught in a stampede to escape.
Inspectors believe the blaze began when a band's small pyrotechnics show ignited foam sound insulating material on the ceiling, releasing a putrid haze that caused scores of university students to choke to death. Most victims died from smoke inhalation rather than burns in what appeared to be the world's deadliest nightclub fire in more than a decade.
Survivors and the police inspector Marcelo Arigony said security guards briefly tried to block people from exiting the club. Brazilian bars routinely make patrons pay their entire tab at the end of the night before they are allowed to leave.
But Arigony said the guards didn't appear to block fleeing patrons for long. "It was chaotic and it doesn't seem to have been done in bad faith because several security guards also died," he told The Associated Press.
Later, firefighters responding to the blaze initially had trouble getting inside the Kiss nightclub because "there was a barrier of bodies blocking the entrance," Guido Pedroso Melo, commander of the city's fire department, told the O Globo newspaper.
Authorities said band members who were on the stage when the fire broke out later talked with police and confirmed they used pyrotechnics during their show.
Police inspector Sandro Meinerz, who coordinated the investigation at the nightclub, said one band member died after escaping because he returned inside the burning building to save his accordion. The other band members escaped alive because they were the first to notice the fire.
"It was terrible inside -- it was like one of those films of the Holocaust, bodies piled atop one another," said Meinerz. "We had to use trucks to remove them. It took about six hours to take the bodies away."
Television images from Santa Maria, a university city of about 260,000 people, showed black smoke billowing out of the Kiss nightclub as shirtless young men who attended the university party joined firefighters using axes and sledgehammers to pound at the hot-pink exterior walls, trying to reach those trapped inside.
Bodies of the dead and injured were strewn in the street and panicked screams filled the air as medics tried to help. There was little to be done; officials said most of those who died were suffocated by smoke within minutes.
Within hours a community gym was a horror scene, with body after body lined up on the floor, partially covered with black plastic as family members identified kin.
Outside the gym police held up personal objects -- a black purse, a blue high-heeled shoe -- as people seeking information on loved ones crowded around, hoping not to recognize anything being shown them.
Teenagers sprinted from the scene after the fire began, desperately seeking help. Others carried injured and burned friends away in their arms. Many of the victims were under 20 years old, including some minors. About half of those killed were men, about half women.
The party was organized by students from several academic departments from the Federal University of Santa Maria. Such organized university parties are common throughout Brazil.
"There was so much smoke and fire, it was complete panic, and it took a long time for people to get out, there were so many dead," survivor Luana Santos Silva told the Globo TV network.
The fire spread so fast inside the packed club that firefighters and ambulances could do little to stop it, Silva said.
Another survivor, Michele Pereira, told the Folha de S. Paulo newspaper that she was near the stage when members of the band lit some sort of flare that started the conflagration.
"The band that was onstage began to use flares and, suddenly, they stopped the show and pointed them upward," she said. "At that point, the ceiling caught fire. It was really weak, but in a matter of seconds it spread."
Guitarist Rodrigo Martins told Radio Gaucha that the band, Gurizada Fandangueira, started playing at 2:15 a.m. "and we had played around five songs when I looked up and noticed the roof was burning."
"It might have happened because of the Sputnik, the machine we use to create a luminous effect with sparks. It's harmless, we never had any trouble with it," he said. "When the fire started, a guard passed us a fire extinguisher, the singer tried to use it but it wasn't working."