When taxi driver Oliver Easton saw a thick cloud of black smoke billowing from the windows on the fourth floor of Coronation Hospital, in Johannesburg, he knew there was trouble.
"I just thought there was fire. I thought of the children who could have been trapped inside.
"I had to leave my passengers for a while," he said.
Easton, of Eldorado Park, said he had dropped passengers outside the hospital and was waiting for another load when he saw smoke coming from the windows.
He rushed in and found about 12 people inside an operating theatre that was engulfed by smoke.
"I managed to get out five people. We helped others until the emergency services arrived to extinguish the fire," Easton said.
Johannesburg emergency services spokesman Malcolm Midgley said the fire was started by a machine used by anaesthetists. The fire did not cause serious damage and he did not know the cause.
"It took us an hour to put it out completely," said Midgley.