The first reports were up on Twitter within seconds - so often the case now.

As Christchurch's electricity flickered then failed, the city's shaken residents stumbled blearily from their beds to the doorways, mobile phones in hand to announce the earthquake to the world.

The time was 4.36am.

Radio stations cut away from their graveyard programming to begin taking calls from scared and excited residents, and online news sites began reporting a big tremor that had damaged roads and buildings.

The Associated Press international newswire posted a newsflash at 5.30am.

A Radio New Zealand host put Good Vibrations by the Beach Boys on the CD player, drily observing that it might be a career-limiting song selection.

By now, Christchurch's cracked roads were already clogged with cars heading in the direction of the Port Hills, as people grimly remembered the Boxing Day tsunami that hit South Asia in 2004.

It was not until about 6am that the Ministry of Civil Defence posted its first alert, and announced it had activated the National Crisis Management Centre.

The first official police statement came a few minutes later, at 6.05am, from Inspector John Doherty.

A few short sentences - damaged buildings, ambulance reports of minor injuries.

"It is recommended that people take care if they have to travel as there has been damage to some roads," he said.

Too little. Too late.

The appropriate emergency response to an earthquake is very different to a tsunami threat. A tidal wave leaps silently from the ocean: the Ministry of Civil Defence's duty is to wake up coastal residents and evacuate them before it arrives.

An earthquake announces itself, in violent terms. If you've been hit by a big earthquake, you don't need Civil Defence authorities to wake you up and tell you so. The priority of police and emergency services, then, must be to handle the aftermath. Containing panic is even more important than helping the injured, because panic leads to more and greater harm.

Yesterday morning, within an hour of the quake, hundreds of people were loading their families and photo albums into cars and pulling out on to the main roads - roads that were cracked, even liquefied, roads on which the traffic lights were out.

Still more people hit the streets out of pure curiosity, excited to see the damage caused by an earthquake that might be "The Big One" most New Zealanders have been anticipating all their lives.

And where were the calming and authoritative voices telling them to stay in their homes? TVNZ, the state broadcaster, had nothing but grinning Paul Henry reruns until after 7am. Perhaps they figured that as the power was out in many parts of Christchurch, there was no point bothering - not enough ratings points.

Where was the stirring national political leadership, telling residents how they should look out for their families, check on their elderly or vulnerable neighbours, and avoid hasty over-reactions? Who knows.

Maybe home looking out for their own families. Labour's Christchurch Central MP, Brendon Burns, went on TV at about 7.30am - to talk about the damage to his house.

Government ministers Gerry Brownlee and John Carter finally turned up at the Beehive at 8.30am - four hours after the quake. Carter, the civil defence minister, said he had not yet spoken to the Prime Minister.

It could have been an episode of Dad's Army. We're going to have a conference call, said Carter. "Don't panic."

By the time the Government finally put John Key on an Airforce plane to Christchurch yesterday afternoon, any chance of demonstrating real, unifying leadership was gone.

Yesterday, the authorities didn't lead - they followed.