Santa Maria, Brazil (CNN) -- The teacher who lost four students. The mother whose son died, while another clings to life. The photographer who survived but is haunted by guilt.
As the southern Brazilian city of Santa Maria began to buzz again Tuesday with cars and people, a somber mood still ruled the streets, where a nightclub fire Sunday claimed 235 lives.
Just about at every corner you could hear angry voices raised in talk about who is to blame for the massive blaze at the Kiss nightclub. Protesters rallied, demanding justice for those killed and tighter enforcement of regulations.
In addition to the deaths, 74 people remain hospitalized in critical condition, Brazil's health ministry said.
In Santa Maria alone, 100 of the dead were buried Monday in three different cemeteries.
That night, the streets were filled with thousands of mourners who marched to the burned-out club.
The shouts of grief and prayers were overtaken only by the wailing of mothers who stood before the building. One woman shouted: "My son, why did you have to die here?"
Police have questioned about two dozen people, including four individuals they arrested -- the two owners of Kiss, a member of the band Gurizada Fandangueira and a promoter.
Police identified the club owners as Mauro Hoffman and Elissandro Spohr. Band vocalist Marcelo de Jesus dos Santos and show producer Luciano Bonilha were also in custody.
Kiss was filled well beyond its legal capacity, when a crowd of 2,000 people packed the club to hear the band play.
About 20 minutes into the concert, the musicians ended a song with pyrotechnic effects. The ceiling caught fire, state officials said. It spread fast.
The crowd panicked, breaking into a stampede, and it hit a bottleneck -- the only exit was the front door, down a dark, narrow hallway.
It clogged quickly.
A firework set off in the club was not made for inside use and the band, which purchased it, knew that, said Marcelo Arigony, with the Santa Maria police. He accused the band of intentionally purchasing the firework made for use outdoors because it was cheaper.
He also said investigators have found evidence of faulty and fake fire extinguishers at the club, which had expired fire and municipal licenses. The club's original license permitted just 691 people inside.
While the investigation centers on the pyrotechnics used, Gurizada Fandangueira's guitarist told the newspaper Folha de Sao Paulo that it was not clear yet what may have caused the fire.
"There were many wires on the ceiling, and there could have been a short circuit," he said.
More stories emerge
For residents of Santa Maria like Vinicius Serafim, the tragedy that unfolded at the club was unthinkable, even as the first reports began to come in.
"Most of us were thinking, 'OK, there is a fire, people got out and that was it," he said. "In the morning, where they started saying 40 dead, 50 dead, then we started noticing and really knowing (what happened)."
Serafim, an English teacher, lost four students in the blaze, and others are in intensive care units.
"Everybody is completely destroyed because they were young people, people that we knew. We worked with them for at least one year," he said.
One survivor, 24-year-old Mariana Magalhaes, told Brazil's state-run Agencia Brasil news agency, that she witnessed the band's singer unsuccessfully trying to put out the fire with an extinguisher.
She was working as a photographer at Kiss, and had already been to 15 funerals when she spoke to Agencia Brasil.
Magalhaes was one of the first to exit the building, and admits that she felt she was overreacting at first by screaming and running out. Only later did she realize her panic saved her life.
"No one could imagine the seriousness (of the fire)," she said. One danger was that the club's sound insulation was made of styrofoam, which releases toxic fumes when burned.
"It was a very silent enemy," she said. "People were exiting fine and walking, when from one moment to the next they started to fall, to have convulsions, to vomit."
Magalhaes escaped with five friends, but in the immediate aftermath of the tragedy she was filled with guilt, too.
"You can count five people on one hand," she said. "We don't feel fortunate for surviving because there are mothers who won't be able to hug their sons. My mom is hugging me, but at the same time I felt lucky and guilty."
On a Brazilian television program, one mother lamented the death of her son and the injuries to a another son.
Elaine Goncalves was able to locate her injured son as he was being transferred to a hospital, but she could not accompany him because she had to go claim the body of her other son.
"It's terrible, very sad," she said. "My sons left the house looking nice, happy, playful, the two brothers together. My son left to go to a party and now he is here, inside a box. I demand justice."
President: 'Indescribable' pain
Brazil's minister of health, Alexandre Padilha, said the most serious cases involve patients who require permanent dialysis, medications to maintain blood pressure, and assistance breathing.
Many of the injured were transferred to hospitals in bigger cities, while others were kept in Santa Maria.
"The transfer was for patients with serious burns because our specialized centers are in the city of Porto Alegre and also in order to free up beds in the intensive care unit here in Santa Maria," Padilha said.
Some were in such critical condition that it was not believed they could survive the trip to another facility.
Brazilian President Dilma Rousseff honored the victims during a meeting with newly elected mayors on Monday.
"The pain which I witnessed is indescribable," Rousseff said. "I speak of that pain to remind us all about our responsibility, the executive branch, with our population. In the face of this tragedy, we must make a commitment to ensure that it will never happen again."
Helena de Moura reported from Santa Maria, and Mariano Castillo from Atlanta. CNN's Shasta Darlington and Alejandra Oraa contributed from Santa Maria and Umaro Djau, Ben Brumfield and Marilia Brocchetto contributed from Atlanta.