Rescue teams were pressed into service, working into the night after a mall under construction caved in on Tuesday (November 19), killing one person and trapping up to 50 more near the South African city of Durban.
It was not yet clear what caused the collapse, although Deputy Mayor Nomvuzo Shabalala said local authorities had tried to halt construction at the site, alongside a railway, a month ago.
A further 26 people, some in critical condition, were rushed to hospital in Tongaat, 20 miles north of Durban, Chris Botha, a spokesman for the Netcare 911 emergency service said.
A high death toll could also sour labour relations in the construction sector, which has an otherwise decent safety record due to the strength of South Africa's unions.
As darkness fell over the site, scores of rescue workers and police combed the broken concrete slabs and twisted bits of metal, illuminated by powerful arc lights.
Sniffer dogs roamed through the debris looking for survivors as large crowds of onlookers and anxious friends and relatives gathered in the darkness behind a security cordon.
Ambulances ferried the injured to nearby hospitals, which initiated full-scale disaster plans.
If safety regulations are found to have been flouted, the accident could hurt the ruling African National Congress (ANC) as it moves towards an election next year.
Presented by Adam Justice