It was initially reported that 50 more people were feared trapped, but the site foreman told rescue workers they may have already left for home, as the slab caved in while they were knocking off.
Sniffer dogs were combing the scene for survivors late on Tuesday night. Spotlights were lighting the area, which was described by Netcare 911 spokesman Chris Botha as being around the size of a soccer field.
Paramedic Neil Powell told the French news agency Agence France-Presse (AFP) that most of the injured had broken bones and crush injuries.
“Some are in severe condition, others are mild,” he was quoted as saying.
Heat-seeking equipment had detected three “hot spots” where other survivors could be located, AFP reported.
Fibre-optic cables were being fed into the area to determine if anyone else was alive.
KwaZulu-Natal premier Senzo Mchunu expressed his shock at the accident.
“We express our condolences to the family of the person who died in this horrific accident,” he said in a statement.
“We also wish those who were injured prompt recovery.”
He said he was liaising with health MEC Sbongiseni Dhlomo to ensure the injured received quality healthcare at public health facilities.
“Importantly, I am confident that all the relevant departments such as the department of labour and eThekwini municipality will help speed up an investigation into the causes of this accident,” Mchunu said.
Earlier, eThekwini deputy mayor Nomvuzo Shabalala said construction at the mall should not have been taking place.
“We took them [the contractors] to court a month ago. We thought they had stopped,” she said.
It had approached the court because the contractors had not “followed processes”.
Fiona Moonean said she was washing dishes when the slab collapsed, directly over the railway line from her home.
A few days earlier, workers had started removing the scaffolding supporting the level, she said.
“Just after 4.30pm it was a thunderous sound. Before the bang, I heard too much scaffolding fall. That’s when I picked my eyes up [and looked through her window at the mall].
“The whole concrete slab crashed down with the pillars. The smoke and dust was too thick. I heard them screaming out for help in Zulu.”
She called the emergency services and a woman took down her details.
“She had to calm me down because I was so freaked out. For me, the most traumatic is the sound of the guys’ voices. That is the part that plays in my head,” she said.
Lieutenant Mandy Govender said earlier on Tuesday evening that almost the entire area of the construction site in the mall was down.
“We are still combing the area with sniffer dogs searching for survivors. All the workers are not accounted for at this stage. Emergency services are on the scene as we speak.”