By David Loyn
World affairs correspondent, BBC News
There have been several shooting incidents in Germany in recent years
Wednesday's attack in Germany was not an isolated incident.
The last school shooting in Germany on the same scale as today's was as recent as April 2002 in Erfurt, where 17 died including the young gunman.
And there have been several other incidents in the intervening years where the death toll was less, but the shock as great - the dark underside of one of the world's most ordered societies.
Chancellor Angela Merkel may have chosen to restrict herself to a brief statement of condolence.
But after Erfurt her predecessor Gerhard Schroeder was prepared to speak the unspoken thought, saying: "There are questions we have to answer here as a whole society."
In all cases, the shootings were carried out by lone male killers in their late teens, and their victims were teachers and pupils in schools they were either at or had recently left.
They were often intelligent, but where they left notes they saw themselves as failures.
A note left by one, known only as Sebastian B, in 2006, said: "What's it all for? Why should I work? To break myself and retire at 65 to die five years later."
He killed himself after shooting and wounding 37 others, not killing anyone else, although he had planted explosives throughout his school in Emsdetten, near Munster.
When Sebastian B carried out his attack, he had been due to appear in court to answer charges of possessing an illegal handgun.
As a minimum response, there will be calls to limit violent computer games and put further restrictions on gun ownership.
The killer on Wednesday appeared to have access to guns at home, like the youth who carried out the Erfurt attack in 2002.
German laws were tightened after that massacre, increasing the minimum age for purchasing guns from 18 to 21, banning pistol-grip shotguns and outlawing certain types of knives.
But restricting ownership further, while still allowing recreational hunting - a popular sport in Germany - will be hard to do.
European Union states have already agreed to harmonise their laws by 2010, to ensure that guns are sold only to people over the age of 18 who are not deemed a threat to public safety.
Finland, where there have been two attacks on schools within a year, has today announced plans to increase the legal age for handgun ownership from 15 to 20.