The finance offices of the Gauteng premier's department were on Friday morning destroyed in a blaze apparently caused by an electrical fault with a plug, Premier David Makhura said.
"Nevertheless, we have an off-site back-up, particularly of the files," he said, assuring the public that all documentation was safe – and that the fire had been contained.
All 280 staff members were evacuated from the offices within minutes, and no injuries were reported – although some people were being treated for shock.
Mahkura left the ANC policy conference at Nasrec, near Soweto, to attend to the emergency. He said a staff member had seen the fire start at 08:40 on the 7th floor from an electrical plug. "Someone saw the exact cause of the fire."
The premier praised operations by disaster management, rescue services and the police – saying that since the recent Grenfell Tower fire in London, he had been particularly concerned that the province would be able to deal with possible similar situations.
"All the time we have been asking our infrastructure department that all should be in order."
Makhura said he had wanted to ensure that the province had the "capacity to save lives and out the fire as quickly as possible".
"We are pleased that there is no life lost," he added.
Additional reporting by News24