There are some dates you don't forget. For me, Tuesday 17 October 1989 is one of them.

It was a funny day right from the start. I'd gone into San Francisco to finalise some travel details. I had to go downtown and found a car park straight away, which was weird in itself. Market Street was bare. There was nobody there. Someone could have fired a shot down the street and not hit a soul.
Also unusual was the fact that I wasn't working late for the first day in three months. In fact, I was leaving early to specifically avoid the baseball traffic at Candlestick Park later that day. It was game three of the World Series, where, also oddly, the play-offs were an all-Bay Area affair between the San Francisco Giants and the Oakland Athletics.
It was a stunning day, very warm for that time of year in Northern California. Driving south to the small coastal town of Half Moon Bay where I lived, I remember thinking that old-timers in my family would have called it ‘earthquake weather.' Growing up on the coast north of Wellington, tremors are a fact of life.
Revelling in the unaccustomed free time, I decided to read the paper before going for a run. It was 5pm, I had the house to myself and the sun was streaming through the open front door. I poured a small glass of juice and sat at the table. The window rattled slightly and I thought 'Oh, it's a wee quake” and turned the page.
And the very next second, the world went mad.
My juice slopped right across the newspaper. The floor rose fully two feet before falling and rapidly rising again in succession. 'My God,” I thought in panic. 'It's the big one!” I ran across the lounge to the big wooden double front doors, hugging on to the locked one with both arms and legs, but the force of the movement saw me repeatedly thrown to the ground. Our house was barely 400m from the beach, just off US1, the coast road, where the cars were bouncing on all four wheels in a macabre lamb-like depiction while the large concrete telephone poles were swaying metres. I still don't know how they didn't snap. Insanely, I was scared that I was going to be seriously injured by Scott's vast CD collection that was only a few feet away, but thankfully the shaking occurred in the other direction. I was shouting but I couldn't hear myself. Later on, I realised that the incredible noise must have been the seabed itself.
Then it was over. If you've ever been in a car accident, you know that fear can play games with time. The 20 second duration felt like minutes.
I went into autopilot. The power and telephones were out, but as I couldn't smell gas I left well alone, having been told that turning it off when there isn't a leak can be more of a nuisance. I jumped into the car and checked the radio. There was nothing on the FM band, but I found one solitary operational AM station where the dazed announcer was saying that if anybody could hear him, we'd just had a massive earthquake but he didn't know if they were even broadcasting. I noticed a strange car in my driveway, so approached it and knocked on the window. A man with a face as white as his vehicle looked up and wound down the window.
'What the hell just happened?” he asked.
'One minute I was driving along, enjoying the scenery and the next, my car was bouncing and the road was going up and down like waves! I pulled off the road and yours was the first driveway I happened upon!”
I looked down and spotted his Florida license plates. It transpired that it was his first trip to California and I imagine that he will never forget the date either.
The aftermath was hard going. There were 400 shocks registered over the next six weeks. The Bay Bridge that links San Francisco with Oakland was closed for a month when an upper section collapsed. A two-kilometre upper section of Oakland freeway just off the Bay Bridge collapsed onto its lower section crushing 40 odd vehicles in an instant. It took years to fix and was deviated in the process. Thousands were made homeless and in spite of the initial media predictions of hundreds dead, a total of 67 people lost their lives.
But with the utmost respect for those 67 families, it could have been so much worse. The earthquake measured 7.1 on the Richter Scale, occurring at what should have been peak rush hour traffic, but because the World Series was on, and featuring both local teams to boot, most people had either left early to watch the game at home or stayed at work to do so. The roads were abnormally quiet for what should have been a regular Tuesday evening.
The Bay Area Rapid Transit (BART) proved to be a godsend in the interim. Designed to withstand a major earthquake, it was closed for 24 hours for inspection, before being passed fit for service. Its daily passenger numbers rose by 50 per cent.
Getting around was a nightmare with so many road closures, both temporary and longer term; the problem magnifying where bridges were featured. I had a 35 mile commute from the coast across the San Mateo bridge to the East Bay, so packed up what I needed and lived at work during the week, returning home at weekends. One Friday I decided that I'd had enough and left early. Knowing that I'd hit traffic, I took some work with me.
It seemed that everybody had the same idea, so much so that nobody was going anywhere fast. The freeways were jammed. All engines were switched off with people chatting through open windows, exchanging quake stories, magazines and cassette tapes. I decided to give myself a manicure, discovering in the process that steering wheels are ideal for that. The guy in the car next to me asked to borrow my nail polish when I was finished. Correctly guessing my expression, he grinned.
'No, I'm not gay”, he said. 'I'm married with two kids. But I'll do anything to avoid going nuts in this traffic.”
'Go for your life!” I said, 'and give it to your wife with my compliments. It's good stuff!”
My regular 45 minute commute took six hours that day. It turned out that there was total gridlock everywhere for 50 miles.
That was 20 years ago last Saturday and I remember it clearly. In fact, I recall it every time I hear people say that human beings affect the planet. In my opinion, those people can't have experienced a serious natural disaster.
How lucky for them – because I was under no illusion as to who was in control that day

Guest post by Susan Ryder