STORY: 34-year-old construction worker Moses Malala recounts how he emerged unharmed after a building collapsed on Monday (May 6) in the South African city of George, trapping dozens of workers.

That day, he was on the roof of the building.

"Was on the last floor on the roof, on the roof slab. And then (it was) starting to make big, big, big, big noise, big sound coming from down. And then the dust is coming up and then now one who I can see, where is my friend, where is who...what, what. Ya we can't see nothing just the building was starting go down."

He also shared how he is now struggling after one of his colleagues died.

"Every night I can't sleep. Because since Monday, we are here on the site every day to check our guys."

The multi-storey building was being built when it collapsed, killing several people.

Seventy five workers had been on the construction site. Many are still unaccounted for.

Rescuers were using cranes, drills and their bare hands to try to reach dozens of people trapped.

Liatel Developments, the contracted builder of the structure, said it was trying to assist those on site.

Authorities have made no comment about what caused it to collapse.

President Cyril Ramaphosa has called for an investigation.