"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."