Like just about every New Zealander, I remember clearly what I was doing at 12:51pm on Tuesday 22 February 2011.
I was holding a meeting with a group of people from Business New Zealand in my office on the ninth floor of the Beehive in Wellington. We were going through a number of issues when there was a reasonably violent shake and everyone stopped talking. It carried on for a few moments. We thought it was just another shake in Wellington and didn't think much of it at that point.
Probably about two or three minutes later my door opened and my Chief of Staff came in and said, "that wasn't an earthquake in Wellington - it was an earthquake in Christchurch".
It was at that point we realised it was obviously a very significant shake to have felt it so distinctly here in Wellington so the meeting ended pretty much immediately.
Then, as quickly as we could, we tried to get a sense of what was happening in Christchurch. Our first worrying fear was a major earthquake had taken place at a time when Cantabrians were going about their business. It was a very busy time of day, with people at work and children at school.
It quickly became clear that my old home town had suffered enormous destruction and it was likely lives had been lost.
Immediately, I thought of my sister and her family who live in Christchurch. I sent her a text asking if she was okay. Thankfully she was able to text me back to say she was okay but she told me it was really bad.
I made the decision I needed to get down to Christchurch for a firsthand look as quickly as possible to assess the situation and identify what resources we needed to mobilise at a national level to help the people of Christchurch.
From the moment the earthquake struck, things began to move very quickly - the National Crisis Management Centre in the bunker of the Beehive was activated and information began to trickle in. Communications out of Christchurch were limited.
We were due to go into the House for question time at 2pm, but that was cancelled once we realised just how serious the situation was in Christchurch. Instead I went down to the House and gave a brief Ministerial Statement on what we knew at that point.
I called an emergency Cabinet meeting for 3pm that afternoon. Immediately after that, I jumped onto a King Air flight to Christchurch. While I was in the air, Deputy Prime Minister Bill English gave a press conference in the Beehive at 4:15pm with the latest developments. It was a fast-moving situation - details were sketchy and rumours were rife. We wanted to get as much accurate information out as possible to keep New Zealanders informed of what was happening in our second-largest city.
Once I arrived in Christchurch, we drove into the central city and went to the Civil Defence emergency centre, which had been established at the Art Gallery. There was quite a state of shock and panic - there was a lot of noise, a lot of sirens blaring, and helicopters with monsoon buckets whirred overhead. It had obviously been a huge earthquake and people were quite shaken. It was just a sheer state of chaos - dust was heavy in the air, roads had been ripped apart, and there was also a really thick smell of smoke in the air.
After talking to the Mayor and Police at the Art Gallery, I went down to Latimer Square to give an update to the media. While I was there, I looked down the road and could see the CTV building was on fire. The devastation in that area was just immense. It was everywhere you looked.
When I came down to Christchurch after the first earthquake on 4 September 2010 people were a bit shocked and reasonably quizzical about how bad the damage was, and grateful nothing really serious had happened. February 22 was a completely different atmosphere as everyone knew it was really bad.
I remember telling the media this could be New Zealand's darkest day. We knew at that point that 65 people had lost their lives and there may be many more casualties.
During the course of the day, I was focused on trying to deal with the issues that were coming up, and ensuring we had all of the resources deployed. It was a full-scale emergency. We were worried about people being trapped in buildings, we were in the process of trying to mobilise the international effort, including the Urban Search and Rescue (USAR) teams. While this was happening, there were very violent aftershocks rocking the city, which were quite intimidating.
At one point during the day, I remember thinking, 'this is the city I grew up in, I knew it really well, and it was destroyed'. It was like a war zone. Christchurch was a city that had been brought to its knees. The noise, the smell, and the people are the things I will remember most about the day.
To a degree, there was a sense of hopelessness. On the other side of the coin, there was a lot happening. We were doing everything we could but the sheer scale of it was a bit overwhelming for everyone.
Overall, 22 February was a bit of a blur but moments from that day and the days following will remain etched in my mind, as I witnessed first-hand just how destructive nature could be.
One of the most heart-warming things was the huge outpouring of support and grief we received from other countries. From memory I had calls from a number of foreign leaders including Australian Prime Minister Julia Gillard, UK Prime Minister David Cameron, and US President Barack Obama, as well as the Queen and the Prince of Wales all offering their sympathies and support. The Australians were remarkable - they just dispatched resources and nothing was too much of a problem. I remember seeing on TV the Australian Police landing in Christchurch Airport and everyone just stopped and started clapping. That was one clear example of the sense of family we share with Australia. In the end, many other countries also offered their support over the coming days. I can't thank them enough for that support.
Long term the Christchurch CBD will look much different to what it did in the past. I think it will be vibrant, it will be new, and it will be a great place to live.