Traffic was gridlocked in the Joburg CBD, with motorists stranded on the road for hours in the deluge.
Sebokeng, Cosmo City, the Joburg CBD, Sandton, Ekurhuleni, Zandspruit and Krugersdorp were the worst affected.
The hailstones in some areas were reported to be the size of golf balls, causing severe damage to private property and a loss of life in Krugersdorp.
One person was killed and two others were hospitalised after a tornado struck Hillside Road in Krugersdorp, according to Netcare 911 spokesperson Nick Dollman.
ER24 paramedics were called to Cradlestone Mall in Krugersdorp to render assistance after part of a ceiling collapsed on shoppers.
ER24 spokesperson Russel Meiring said two people were injured when the ceiling came tumbling down in a shop as torrential rain lashed Krugersdorp.
“ER24 paramedics, along with Life Healthcare and other services, arrived on the scene, where they found that some of the external structure of the mall had collapsed.
“Once inside the shops, they discovered that part of the ceiling had fallen onto the patrons,” said Meiring.
Two people were assessed by paramedics. They sustained minor to moderate injuries.
“Luckily, there were no serious or fatal injuries.
“Security guards at the mall evacuated the area while paramedics treated the two patients. Both patients were taken to hospital by ambulance,” he said.
Leah Knott, the DA’s ward councillor for Zandspruit, Honeydew and Ruimsig, said several roads were blocked by fallen trees, and roofs were blown off by high winds when the storm hit the area after 3pm.
Houses were destroyed, sign boards blown over and vehicles overturned in Zandspruit Informal Settlement, which bore the sharp brunt of the storm, she said.
“We experienced a mini tornado in Zandspruit where shacks were blown away.
“Two people were injured by falling debris in their homes.
“In Ruimsig, there was chaos after roofs were ripped off and trees uprooted in residential complexes.
“Several roads were impassable,” she said.
“Looting was reported at a Ruimsig office park and cable theft in Pierre Street, but we called the police and they dealt with that situation,” said Knott.
Managers of Cradlestone Mall in Krugersdorp refused to comment last night, saying they would release a statement today.
However, pictures posted by witnesses on social media showed a huge chunk of the ceiling at Food Lover's Market and Virgin Active had been blown off while a section of the centre’s outside decorative structure fell on top of cars.
On their Twitter account, Cradlestone Mall said it would be closed until further notice.
In other areas in Gauteng, trees and roofs were blown away, causing traffic gridlock in many areas.
Johannesburg Emergency Services spokesperson Nana Radebe told The Star that they received calls that trees had fallen in Sandton and Marlboro.
“Fortunately we have not received any reports of injuries that resulted from the storm.
“We have received reports of floods around the Jukskei River at Alex and Diepsloot. EMS deployees are monitoring the river levels,” said Radebe.
Meanwhile, Ekurhuleni experienced a severe explosion in the Boksburg area, but no fatalities were reported.
Ekurhuleni EMS spokesperson William Ntladi said: “We can confirm that an electrical substation caught fire in Jet Park, Boksburg. That might be as a result of the weather that we experienced earlier on; however, we have already dispersed our resources.”
Firefighters were deployed to the scene to manage the disaster.
“In Etwatwa, Daveyton, a number of houses are affected and some of them had their roofs blown off. We don’t have the exact number of houses affected.
"We have also sent our resources to assist.
"On the N3 and N12 split there are a lot of floods, with water flowing across the freeway, with a lot of debris,” said Ntladi.
He added that the Ekurhuleni EMS had been deployed to all known hotspot areas to assist with the aftermath of the storm.
A few flights were delayed at OR Tambo Airport International Airport at the height of the storm, said airport spokesperson Leigh Gunkel- Keulert.
“There was a slight impact earlier with a few delays but we have caught up and we are now back to the normal schedule,” she said.
Kelden Naidoo, who was catching a 3.50pm flight to East London with his family, said their plane was delayed by two hours.
“We waited for about 45 minutes to board, and once we boarded we had to wait for another hour to depart.
"We were being told that flights that wanted to pour fuel could not and passengers from planes that landed could not disembark because of hail. That delayed everybody, and people were getting frustrated,” said Naidoo.
The South African Weather Service had earlier warned Joburg residents to prepare for possible severe thunderstorms.
“Residents must prepare themselves for thunderstorms which can be severe, we will issue warnings which they can find on social media,” forecaster Madimetsha Thema from the SA Weather Service said.
Thema said thunderstorms usually occur ahead of a cold front and could lead to high winds.
While it’s impossible to change the weather, we can still protect our belongings as much as possible, and make sure they will be replaced through adequate insurance if damaged."
Insurance company Standard Insurance Limited released a statement ahead of the storm warning commuters to keep their properties safe.
The company advised that should you find yourself in the path of the coming storms:
“Ensure electrical equipment is disconnected from sockets during storms to avoid electrical-surge damage, check roofs do not have broken or loose tiles that will allow the entry of water.
"Ensure, too, that roof gutters are clean and unclogged, so water does not seep on to ceilings”.