By Botho Molosankwe, Gill Gifford and Sapa
An underground gas leak was responsible for yesterday's explosion that damaged a Telkom exchange in Yeoville as well as adjacent buildings.
It was earlier believed that a municipal transformer had exploded.
One man was in hospital, phone lines were down, pavements were cracked, windows were smashed and damage was still being calculated following the massive blast yesterday morning.
Just after 8am, an explosion occurred on the ground floor of the grey three-storey building in Hunter Street. Two people were injured as the shock waves rippled through the area, leaving cracks in the pavements up to a block away in all directions.
The blast, which ripped open a manhole, left a hole measuring about 5 by 15 metres.
The roof of the building was damaged, the front wall was blown out and the cast-iron manhole cover was tossed over the Word of Life Assembly Church across the road, and landed on the pavement in nearby Kenmere Road.
James Nkosi was driving past in his white Toyota Corolla when a large object hit his windscreen.
The 31-year-old Hillbrow man had just dropped his wife off at work in Eastgate and was driving along when suddenly his back window was blown out, the bumper ripped off, his door was dented and the side of his car coated in mud.
"I thought it was a truck hitting me, but I saw that it was a building falling. More stones started hitting the car and I got inside and drove off. I was very scared... I did not know what was happening. Stones were flying and people on the streets were running in all directions," he said.
Nkosi abandoned his car in the middle of the road and fled, leaving the keys in the ignition. He returned a few hours later after the shock had worn off.
"I feel very lucky to have escaped, but my worry is that I am not insured," he said.
Collin Mayana, who lives in the area, had just returned home from buying a newspaper when the blast happened.
Pointing to a ripple of bricks lifted out of the pavement, he said: "I was standing at this exact spot just 10 minutes before it happened."
Joburg Emergency Management Services (EMS) spokesman Percy Morokane said one man who was critically injured in the explosion was believed to be a Telkom technician who was working on the transformers when the blast happened.
Another woman was lightly hurt, and was taken to Milpark Hospital to be treated for shock.
Morokane said heavy rescue technicians as well as urban search-and-rescue teams had been called in because there was a possibility that more victims could be found in the rubble.
A large area was cordoned off as sniffer dogs and Egoli Gas technicians arrived.
Children from a nearby nursery school were evacuated as a precaution.
Nomsa Makhudu sobbed hysterically behind the cordons as she had been unable to find her cousin, who works as a security guard at Telkom.
She was guided to the scene by concerned EMS workers who took down the information. She was comforted, and was then thrilled to hear that it was her cousin who had been taken to hospital.
A short while later, the rescue efforts were called off as it was confirmed that there were no missing people.
Morokane said while the exact cause of the blast was not known, the investigation was to be handed over to Telkom.
Telkom issued a statement saying the explosion had been caused by a "municipal transformer" at the Yeoville exchange.
"A small segment of our voice, data and DSL customers in the Yeoville area are impacted. 60 mobile links are also affected," said spokesman Ajith Bridgraj, "Telkom is in the process of assessing the situation."