As sheets of rain turned to torrents, nursing sister Sandy Taft saw a pale cloud, tinged by a strange blue light - "like a police light" - descend over the roofs of Manenberg.
"It was a heavy, evil thing, like a grey, grey rain wind," she said, describing how the storm touched down, brushing aside roofs as a child's feet would knock over building blocks.
Waiting for the bus alone on the corner of Jordan and Duinefontein roads shortly after 6am, Sandy Taft was one of few people to actually see the terrifying force which cut a swathe of destruction through Surrey Estate, Manenberg and Guguletu, killing five people, including a baby, leaving 5 000 homeless and injuring more than 180.
Then she heard an explosion and saw sparks fly as electricity lines went down.
"I said to myself, 'Here I go', but it didn't touch me."
Shaken and terrified, she turned back home, to the sound of the first sirens responding to the disaster.
Although weather experts are reluctant to refer to the storm as a "tornado", it had all the hallmarks of a twister.
Winds of more than 150km an hour ripped through a narrow strip of one of the most densely populated parts of the city, and people cowering in their homes described a roaring sound like an aircraft landing.
Cape Town weather office forecaster Steve Medcalf said on Monday that although nobody saw a column of spinning air at the time the damage was caused, "in retrospect all signs show it probably was a tornado".
A tornado was classified as a violently rotating column of air hanging from a thunder cloud and was nearly always observed as a funnel. "It is the most destructive of all atmospheric phenomena."
Meteorologist Chris Reason, a senior lecturer at the department of environmental and geographical sciences at the University of Cape Town, said: "The accounts of the incident and the resulting damage seem to be consistent with what might be expected of a tornado, but sufficiently detailed observations do not exist to confirm this."
Forecaster Rian Smit said the cell of low pressure came in from the north-west and reached its peak over Manenberg and Guguletu about 6am.
Although the peak velocity of 80 knots (hurricane level) lasted only a few minutes, that was long enough to cause the damage.
More rain and wind on Monday and Tuesday are likely to hamper mopping-up.
The problems for those affected by the disaster are far from over. On Sunday night, three community centres which had been set up as shelters and stocked with food and hot soup remained empty.
This was because residents were too afraid to leave their goods unguarded, for fear of looting.
Instead, the helpers decided to take food to people in their battered homes. A rescue volunteer said unless residents could find trucks to cart away their belongings, they would not leave.
The City of Cape Town has pledged R1 million to form the basis of a mayor's disaster relief fund, and President Thabo Mbeki is to be asked to declare the storm-damaged swathe an emergency area.
Scores of flats, especially top-storey units in Jordan Walk and in surrounding blocks were demolished by the powerful wind. Roof materials were blown as far as Cape Town International Airport, where they landed on the runway, as debris rained down on the streets nearby.
In Duinefontein Road, the wind wrapped corrugated-iron roof sheets around street poles as if they were tinfoil.
Within minutes of the first call, the city's disaster management team swung into action. A huge contingent of medical, police, defence force and traffic personnel descended on the scene.
Ambulance staff ferried people to the nearby G F Jooste Hospital and later helped transport food into the area.
The hospital's medical superintendent, Norman Maharaj, said night staff had been about to go off duty as the first victims arrived, but stayed on to help. Other staff came in to volunteer their services.
Large parts of the area were left without electricity and emergency generators were called in to help pump sewage to avoid an overflow. Council workers battled throughout the day to restore power so that at least the street lights could work to aid patrols.
Soon after the disaster scores of looters were seen removing valuables and the army was called in to help patrol the area. Neighbourhood watches, from as far away as Mitchell's Plain, offered to assist and carry out patrols.
By the afternoon people were moving what was left of their furniture. In devastated Alpha Court, Manenberg, which looked like a war zone, there was a sense of desperate urgency as people tried to move their goods before nightfall and more rain.
The emergency services of Tygerberg and Cape Town were praised by Cape Town city manager Andrew Boraine for their speedy reaction and co-operation.
Premier Gerald Morkel said he had seen the area from the air and had decided it "should be declared a disaster". He did not doubt the city's ability to cope, but many people had lost all their possessions and many of these had no insurance.
Minister of Social Welfare Zola Skweyiya jetted in from Pretoria. He lauded the emergency services and said he saw the disaster as "a national emergency".