Although a shocking attack, this is a rare attack.
It’s hard to think of another occasion when a teacher was stabbed inside their school by a pupil.
There was the tragic murder of the head teacher Philip Lawrence nearly twenty years ago who was stabbed and killed near the school gates when he went to break up a fight.
Last year according to the Government’s figures 250 pupils were caught with weapons in schools, that’s down by about a hundred on previous years. And in 2011/12 some 550 pupils were expelled for physically assaulting a teacher.
And a recent union survey found a fifth of teachers had to deal with physically aggressive students.
The government did bring in tougher rules a few years ago so teachers could search pupils if they suspected they had weapons on them.
The last Labour government announced in 2008 there would be airport style metal detectors put in hundreds of schools.
Some schools have installed them but they haven’t become widespread as many schools just didn't feel the need for them and didn't want to turn schools into fortresses.