Rescuers from Johannesburg Emergency Management Services have made contact with a fourth man trapped at Power Park in Soweto since early this morning when part of the old power station collapsed.
EMS staff are removing rubble, including slabs of concrete, to reach the metal scavengers.
Johannesburg EMS spokeswoman Nana Radebe said rescuers are in verbal contact with two of the trapped men. Paramedics are on site to work on the victims once they are pulled out.
Maria Matsinhe earlier told The Times that said she received a call from her husband at 5am saying that he was trapped.
He told her that six other men had been with him and one of the trapped is her brother Bhekumuzi Mahlangu.
Matsinhe's husband was able to free himself from the rubble and contacted emergency services. He is now in Chris Hani Baragwanath hospital, with injuries to his hands and legs.