The path of devastation was about 4km long and 400m wide.
The tornado made landfall at Blaketown just after 1pm and moved quickly across town.
Officially, it had an F1 rating with winds speeds of about 180kph.
The insurance industry payouts totalled $9.2 million at the time, about $15.2m in today's money.
It first walloped into the Blaketown Rugby Clubrooms and from Collins Street it twisted across the lagoon into Swainson St.
On the Blaketown side of the lagoon, Allan Devine Engineering lost part of its building, while on the opposite side at Westfleet, vehicles were thrown into the water.
Smiths Speed and Spares, the Auto Village Complex and Aratuna Freighters in Arney Street were next (to name but a few), then as it passed straight over the Tour and Charters bus yard the windows of the entire fleet of 14 buses were smashed.
Video Ezy was ripped apart; some of the DVDs were found scattered a couple of kilometres away on the hill behind Greymouth.
NZ Safety, Boc Gas then the mini golf range were slammed, followed by Trans-West Freighters, Dispatch Foundry, Wrightson, Caltex and the Civic Centre, across Alexander St and on to the hillside Kowhai Manor rest home, its last victim.
Urban search and rescue teams were deployed and spent the night securing premises.
Yet, just one person was hospitalised — a visitor who had to be cut from her campervan parked outside the Blaketown clubrooms.
Allan Devine Engineering at the time was based at the corner of the lagoon and the tiphead road.
Julie Devine, husband Allan and three others were upstairs when they heard a roar like a jet engine.
Downstairs, two staff huddled in a digger bucket.
The tornado nicked the corner of the building, blew the doors off and peeled back the roof, Julie recalled today.
Their cherry picker ended up in the lagoon, and their apprentice was shocked to find his very first car, which had been parked on the tiphead, was missing.
It was not until the tide went out that they saw its wheels, upside down in the lagoon.
Craig McMillan was at Dispatch when the power went off.
"I looked outside and saw things flying in the air, and thought it was a tornado," he said today.
He sheltered under the furnace and remembers the noise, and a lot of dust, that followed.
When they came out of their hiding places, staff found a wall had caved in, the iron was ripped off, and the back part of the roof had fallen down.
Dave McMillan, who was in Christchurch that day, said they started building a temporary roof the next day, shifted machinery, and within a week had the machine shop operating again.
"I can't believe 20 years has gone past."
