CAPE TOWN, South Africa (AFP) — The collapse of a multi-story building under construction in the South African city of George has killed at least four people and trapped around 50 more, authorities said Tuesday.

In all, 24 people have been found and pulled from the rubble, four of whom have died, the coastal municipality said in an early morning update, adding that 51 others were still unaccounted for.

A construction crew of 75 people was at the site at the time of the collapse Monday afternoon, the city said in its statement.

“Three teams of rescue personnel are currently working on three different areas within the site of the collapsed building,” it added.

Mario Ferreira, spokesperson for the charity Gift of the Givers, which is assisting at the site of the incident, earlier told Agence France-Presse that rescue workers had “communication with some of the people under the rubble.”

The five-story building, including an underground parking garage, collapsed in the early afternoon for reasons still undetermined.

Photographs shared by the municipality showed a flattened construction site with multiple rescue services present.

The building’s broken roof was still clearly visible atop the pile of rubble as high-powered lights lit up the site.

“There have been people taken out, seriously injured,” said Ferreira.

Rescue operations continued throughout the night with strong floodlights illuminating the cordoned-off site.