Officials at the City of Johannesburg say they have been caught by surprise after discovering an old active municipal gas line which had methane traces detected in parts of it.
Officials are also now saying the cause of the Joburg CBD explosion was “definitely a gas explosion” from a gas leak, but they were still investigating the source of the leak.
They said they were ruling out any foul play by zama zamas, terrorists or vagrants, saying the cause was likely accidental.
Joburg City manager Floyd Brink has given an update on the CBD explosion which has claimed at least one life, damaged 34 cars and left two people critically injured.
Brink is leading a team of officials who have since taken over communication of the Joburg CBD explosion from the likes of Gauteng Premier Panyaza Lesufi and Joburg City Mayor Kabelo Gwamanda.
During a technical media briefing on Friday, Brink confirmed officials had detected the old municipal gas line, which was still active, and said they would be working to close it swiftly.
The cause of the explosion, he said, was a gas leak, but they were still not sure what the source of the leak was.
Johan Lagrange, a civil engineer and a consultant for the City of Johannesburg, ruled out the possibility of any illegal mining activities or terrorism causing the explosion.
He said the old municipal gas line detected had caught officials by surprise as nobody knew about it, and explained that methane gas was detected still flowing in it.
“We are not sure if it is connected somewhere to the Egoli Gas line as part of a distribution line from one of the tenants,” he said, adding that the line was set to be isolated.
Lagrange said the old line was a surprise as nobody knew about it, but they would carry on searching and testing.
He also said there were no people living underground and that they had used drones and other technologies to see what was happening underground.
Brink said the imaging showed no signs of life underground and that there was water which would make it difficult to be habitable for vagrants.
Meanwhile, three people remain in hospital among the 48 people that were injured during the explosion.
Municipal services including water and electricity remain shutdown in the inner city as officials continue with their work.
The city committed to provide food, water and ablution facilities to residents and have posted a fire truck nearby as work continues.