Muhammad Amin was driven mad by grief and despair.

His brother, Naveed Memon, was inside Gul Plaza when a fire broke out in the crowded mall in Karachi, Pakistan’s commercial capital.

Like dozens of others, he remains undiscovered.

“What should I tell my mother when I get home? What should I tell my nieces?” Amin asked.

“My nieces are crying looking for their father – they ask me why he is late. What should I tell them? How can I tell them that their father is dead?”

Gul Plaza is a wholesale market with about 1,200 shops in the basement, mezzanine and three floors, offering a variety of cheap products including wedding dresses, toys, decorations, bedsheets, artificial flowers and baby clothes. Residents of the city visit it in droves, especially before festivals, weddings and other important occasions.

The cause of the fire remains unclear.

But witnesses said the disaster was exacerbated by the rapid spread of the outbreak, a lack of fire exits and the density of shoppers and stalls that packed the building.

Rehan Faisal, the owner of a bed linen shop, said he was able to escape because his shop was located near an exit and he broke in through the door.

He said that while his staff heard there was a fire somewhere in the market, they were not initially concerned because it was some distance away.

“Nobody knew it would spread so much,” Faisal added, saying it only took about “five to seven minutes” before everything “burned before our eyes.”

Shoiab, 19, who works in a decoration shop, said he first heard about the fire on the lower floor around 22:00 local time (17:00 GMT) on Saturday night.

He told BBC Urdu: “Many customers and shopkeepers came over… saying there was a fire downstairs. As soon as I started to understand the situation, the shopkeeper asked me to lock up and get out.”

“Suddenly everything was covered in smoke – we couldn’t see anything, there was panic and chaos everywhere. People were running everywhere. I knew some ways to get out of the square. But the first exit I tried was locked and the crowd was so dense that I couldn’t go the other way.”

Most of the mall’s gates are closed due to the facility’s impending closure. Senior police officer Syed Asad Raza told Reuters that all but three of the center’s 16 exits were locked.

Xiao Yabu is one of the luckier people. He passed out in the smoke, but someone – he didn’t know who – pulled him out of the building to safety.

Another colleague who tried to escape with him is still missing.

The confirmed death toll from the fire is now 27, but more than 70 people are still missing, and the structural instability of the still-smoldering building makes it difficult for rescuers to get inside to assess the full extent of the disaster.

Senior rescue official Dr Abid Jalaluddin Shaikh told BBC Urdu that rescue efforts were slowing down further because the structure of the building was so damaged that it was in danger of a complete collapse at any time. He added that many of the bodies could not be identified and they would need to conduct forensic examinations to confirm the exact death toll.

Meanwhile, crowds of people searching for their loved ones gathered around the building, desperate for any news.

Mohammad Qaiser told the BBC that his wife, sister and daughter-in-law were also among the missing. “They said they were going to the market. The last contact with them was at 20:00, when a fire was discovered. We don’t know what happened to them.”

Kaiser said officials were unable to help them and described how his family was told to go to a burn center and morgue at different times.

Another resident, Haroon, said three of his brothers had been in the building. Two of them managed to escape, but one is still missing.

“My brother called our parents inside the square and asked them to save him. He also called his friends and asked them for help, but no one could save him,” he said.

Survivor Shoaib is also still in the building, hoping to get news from his cousin Faizan, who works in another shop.

“Every morning, I go to work and come home with my cousin. Now, I don’t want to go home without him. I’m waiting for him to be pulled out of the building alive,” he said, adding that his phone has been ringing as Feizan’s family members have been asking him if they have any news.

“I don’t have an answer for them.”

As the search continues, anger grows.

Hundreds of protesters gathered around the building on Monday, calling for accountability.

Karachi Mayor Murtaza Wahab was jeered when he rushed to the scene nearly 24 hours after the fire broke out.

Mohammad Arif, whose nephew is also one of the missing, said rescue efforts did not start on time and “precious lives could have been saved.”

Many residents and politicians said it took rescue officials a long time to reach the building.

Faisal said it took the fire brigade a long time to arrive “while an ambulance that was not even needed had already arrived”.

Reuters quoted the rescue department as saying that the authorities received the first emergency call at 22:38 on Saturday, reporting that the store on the ground floor was on fire. When firefighters arrived, the fire had spread upstairs and engulfed the entire building.

Murad Ali Shah, the chief minister of the southern Sindh province, which includes Karachi, promised to investigate the fire and determine a response time.

As the House of Representatives debated a motion to adjourn the tragedy on Tuesday, lawmakers from across the political spectrum condemned the fire and called for sweeping reforms in building safety, emergency response and urban governance.

The prime minister was among those who expressed condolences and promised action.

But that was little consolation to those gathered in the ruins of Ghor Square.

“This is the third time a building fire has broken out in Karachi’s Sadar area in a while,” Mohammad Arif said.

“How long will this last and how many more people will die?”