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.