Nature violated Christchurch in 2011. The fact hatred and vile beliefs have done it again almost defies belief.
Christchurch is a special place, big enough to have many of the pleasures of a city, from art galleries to cafes to libraries to sport, but small enough to often feel like a village, where six degrees of separation usually comes down to one or two.
In the face of the horrendous losses suffered by the Muslim community, it is hard to not feel a sense of impotence, but I know that Christchurch people will respond with the kindness that emerged in so many ways after the 2011 earthquake. The universal response from friends and family in the city is grief and sympathy for the devastated families.
If concrete help is needed, that will be supplied too, not only from government and council sources, but also from private people, in the way Sam Johnson rallied the wonderful student army to clear damage in 2011.
By sad coincidence my wife Jan and I arrived for a weekend in Christchurch on Friday, about an hour after the shootings began.
The city we love was in a surreal state. A measure of how bizarre and dislocated the atmosphere was that, unable to tune the radio in our rental car, so unaware of the scale of the tragedy, we turned back from a police cordon outside Papanui High School, but kept on to the Northlands Mall.
The full realisation that Christchurch had been rocked again by an horrendous event only came when we discovered that the Countdown supermarket had been locked down, with shoppers trapped inside. It's perhaps a measure of how secure New Zealand usually feels, that only then did we notice how relatively empty the car parks at the mall were.
We drove to the home of close friends nearby on streets that were suddenly ghostly, Papanui Rd, usually one of busiest roads in the city, was virtually empty.
Then we watched with mounting horror the full story unfold on television at our friends' home in Papanui. We could hear the constant roar of helicopters overhead. Police car sirens came closer and then faded into what had been a gentle autumn afternoon.
It is impossible to overstate the disbelief still being felt here. The obscenity of a place of worship being attacked is distressing enough, but somehow the fact it happened in a city finding its feet again makes it feel even more disgusting.
You seize at times like this for courage and decency in the face of evil. You think of the bravery of the young men and women in the police who raced throughout the city.
A 66-year-old woman showed extraordinary courage when, with the gunman at the mosque at Hagley Park still nearby, she stayed to apply pressure to the chest of a badly wounded man. When her only comment on her selfless behaviour to an interviewer was an agonised, "I wish I could have done more", how could you not have tears in your eyes?
For those whose lives have been shattered by the cowardly attacks it's so hard to find words that will offer any consolation.
But there is one thing those mourning today can count on. Christchurch is a city with a big heart, and that heart is also kind.