Funerals began on Monday, as reports continued to emerge about the accumulation of neglect and errors at the packed night spot.
Brazilian police said they detained three people in connection with the blaze and were searching for a fourth. Police Inspector Ranolfo Vieira Junior added that the detentions were part of the ongoing police probe and those detained can be held for up to five days.
Vieira declined to identify those detained, but the Brazilian newspaper Zero Hora quotes lawyer Jader Marques saying his client Elissandro Spohr, a co-owner of the club, had been held.
The paper said police also detained two members of the band that was performing when the blaze broke out in this university town of about 260,000 people. The band's guitarist told Brazilian media he saw flames lick the ceiling after the group's spark machine was deployed.
More than 100 people remained hospitalized for smoke, local officials said. Paulo Afonso Beltrame, a doctor helping coordinate the emergency response, said he was optimistic that those injured would pull through.
"It's impossible to predict what will happen, because they are all in a very delicate state, but there's hope for all of them," said Beltrame, adding that more than 40 survivors had been sent to neighboring cities for treatment of burns and smoke inhalation. "One of the problems we're having here is that all these people need to be on respirators and we don't have enough respirators in the city."
Funeral services were held for several of the 231 victims, most of them college students 18 to 21 years old. Some of the victims were minors. Most died from smoke inhalation rather than burns.
Initial reports suggested the tragedy was the result of a series of failures. Police have said they think the pyrotechnics ignited flammable sound insulation on the ceiling.
Other witnesses said security guards who didn't know about the blaze initially blocked people from leaving without paying their bills. Brazilian bars routinely make patrons pay their entire tab at the end of the night before they're allowed to leave. Many of the dead were found in the club's two bathrooms, where the blinding smoke caused them to believe the doors were exits.
Rodrigo Martins, a guitarist for the group Gurizada Fandangueira, told Globo TV network in an interview Monday that the flames broke out minutes after the deployment of a pyrotechnic machine that fans out colored sparks, at around 2:30 a.m. local time.
"I felt that something was falling from the roof and I looked up and I saw the fire was spreading, and I shouted 'Look, it's catching on fire, man, it's catching fire,'" Martins said. "Then the drummer tried to throw water on it, and it looked like the fire spread more then. Then the security guards came with an extinguisher, tried to use it, but it didn't work."
He added that the club was packed and estimated the crowd at about 1,200-1,300 people.
"I thought I was going to die there. There was nothing I could do, with the fire spreading and people screaming in front."
Martins confirmed that the group's accordion player Danilo Jacques, 28, died, while the five other band members made it out safely. Martins said he thought Jacques made it out of the building and later returned to save his accordion.
Martins said the group nearly always used the so-called Sputnik pyrotechnics machine and that it had never before caused any problem, even in smaller venues. An electrical short circuit could also possibly have been to blame for the fire, he suggested.
Still, police were leaning toward the pyrotechnics as the likely cause of the tragedy. Police inspector Antonio Firmino, who's part of the team investigating Sunday's blaze, said it appeared the club's ceiling was covered with an insulating foam made from a combustible material that ignited with the pyrotechnics. He said the number and state of the exits is under investigation but that it appeared that a second door was "inadequate," as it was small and protected by bars that wouldn't open.
Television images from Santa Maria 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. Teenagers sprinted from the scene after the fire began, desperately seeking help. Others carried injured and burned friends away in their arms. About half of those killed were men, about half women.
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 suffocated within minutes. The fire spread so fast inside the packed club that firefighters and ambulances could do little to stop it, Silva said.
A community gym soon became 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.
The party was organized by students from several academic departments at the Federal University of Santa Maria. Such organized university parties are common throughout Brazil.
Brazil President Dilma Rousseff arrived Sunday to visit the injured after cutting short her trip to a Latin American-European summit in Chile.
"It is a tragedy for all of us," said Rousseff, who began her political career in the state where the fire took place.
Beltrame said he was told the club had been filled far beyond its capacity, and the crowds and thickness of the smoke made it hard for people to find their way out.
"Large amounts of toxic smoke quickly filled the room, and I would say that at least 90 percent of the victims died of asphyxiation," Beltrame said. "The toxic smoke made people lose their sense of direction so they were unable to find their way to the exit. At least 50 bodies were found inside a bathroom."
Beltrame said people who were inside the club and thought they made it out safely have started to turn up at area hospitals with symptoms of smoke inhalation, which he said can take hours or even days to appear. He estimated that around 15 people have sought out help in the past few hours and said some have had to be intubated.
Santa Maria Mayor Cezar Schirmer declared a 30-day mourning period, and Tarso Genro, the governor of the southern state of Rio Grande do Sul, said officials were investigating the cause of the disaster.
The blaze was the deadliest in Brazil since at least 1961, when a fire that swept through a circus killed 503 people in Niteroi, Rio de Janeiro.
Sunday's fire also appeared to be the worst at a nightclub since December 2000, when a welding accident reportedly set off a fire at a club in Luoyang, China, killing 309 people.
In 2004, at least 194 people died in a fire at an overcrowded nightclub in Buenos Aires, Argentina. Seven members of the band playing at the club were sentenced to prison for starting the flames.
A blaze at the Lame Horse nightclub in Perm, Russia, killed 152 people in December 2009 after an indoor fireworks display ignited a plastic ceiling decorated with branches.
Similar circumstances led to a 2003 nightclub fire that killed 100 people in the United States. Pyrotechnics used as a stage prop by the 1980s rock band Great White set ablaze cheap soundproofing foam on the walls and ceiling of a Rhode Island music venue.