What's it like to teach in an area where many young people carry knives and have seen the victims of stabbings? Teachers describe their first-hand views of the knife culture among some young people in London.
"It's not a shock anymore. It's not a surprise anymore," says Angela.
"If something happens in the area, you hope it's not somebody you've taught."
She has been a teacher for 28 years and is currently a head of department at a secondary school in south London.
Last year, a former pupil was stabbed to death.
They were in the wrong place at the wrong time.
The killers included another former pupil, who still had a younger sibling at the school.
"I taught them. I knew them," says Angela.
"It's the worst feeling. It's horrible. They're not the typical cliché kids you know, in a hoody, wearing a mask.
"They're the same students I taught. Got their GCSEs," she points out.
'Part of their culture'
While adults are sickened when knife crime hits their school community, pupils often have a very different reaction.
Angela says the events of last year in some ways did not really change the atmosphere in the school.
"They already know somebody who had been stabbed," she says.
"They know brothers, sisters, people they know who've been stabbed or are involved in gangs. It's part of them. It's where they live. It's really part of their culture now.
"And that's all colours, creeds and ages I would say," she adds.
Angela says the murder case was high profile and the people involved became "sort of stars" locally.
But many stabbings do not result in deaths and "are not public, not big court cases or anything".
She says she knows pupils as young as 11 who carry knives out of fear.
They believe a knife hidden in their own jacket will give them some protection on the streets.
By their mid teens, carrying a knife is "part of the 'I'm part of the gang culture'".
"They're not scared. It's something they are so used to, they're actually not scared," Angela points out.
'Hidden in drains'
Maths teacher Abdul Chaudhury is a National Education Union branch secretary in Tower Hamlets.
Through his union work, he supports staff at the local pupil referral unit for pupils who cannot cope with mainstream school.
Staff there routinely search the area for knives, hidden in drains and bushes by pupils who know they will be confiscated if they attempt to bring them inside.
"Who would imagine that a teacher would have as part of their job, walking around the school building picking up knives?" he asks.
He says knife carrying has become normalised among certain groups of teenagers and the rest of the community are resigned to it.
In the past, he says, people would report individuals carrying knives to the police – but these days there is no point.
"There's no expectation something's going to be done about it," Mr Chaudhury says.
Richard, a primary teacher from east London, says his pupils are fearful, and knife crime is just part of the problem.
A parent at his school died last year after being punched on the street, with a devastating effect on the community.
"When friends and family are the people who have been involved and have been hurt, it's a challenge as a teacher to explain that to children," says Richard.
He says it is no longer possible to explain away stabbings or terror attacks as "one offs".
Back in south London, Angela believes poor communication skills are the root of much street violence.
"It's like they've lost the ability to actually speak to another person and air their grievance," she says.
The first reaction to a problem is too often "a knife or a fist".
Angela adds: "Some think about it for 30 seconds and might start arguing."
"I call it peacocking around you know, but after that, the knife will be coming out."
Kim Knappett, a south London science teacher and a National Education Union vice-president, agrees better communication skills are key.
"I think we're very used to seeing toddlers have temper tantrums because they don't have the language to communicate what they want," she says.
"I sometimes think our young people feel they don't have the language, or don't feel that we would understand their language if they tried to explain how they feel, what's frustrating them, what pressures they're under," she adds.
But she argues that lessons these days are so tightly packed there is little time for discussion, and the subject for personal development, and personal, social and health education, "has been squashed".
Ideally, she would like more money for the "really excellent external providers" who bring ex-gang members into schools to talk to young people their real life experiences.
"A young guy coming in and saying I was in a gang and this is what happened and my mate got killed actually starts to break through to them," says Ms Knappett.
But she says, school budgets are so squeezed there is not enough money to pay for these groups.
So the pupils who need them most, too often miss out.
On top of that, cuts to youth clubs mean many pupils have nowhere to go at the end of the school day, while too many teenagers leave school with few qualifications, and without a job, or the chance of further training.
Angela says, in an ideal world, schools would devote time and money to finding out what these teenagers need "to get out of this gang and this culture".
It is a matter of "giving these children hope", she says.
"They don't see life beyond their area. There's no hope and there isn't any sort of progression. They are just in this cycle," she argues.
In a climate of cuts, Angela fears this kind of intervention could be a long time coming.
But she feels both pupils and teachers need more help, particularly when "something has happened, because it is going to happen again".