Prince Harry and the Duke of Cambridge met survivors of the Grenfell Tower fire during a visit to a new centre providing psychological support to those affected by the blaze.
Prince Harry urged schoolchildren affected by the fire to be there for each other as they come to terms with the tragedy.
Harry has previously said he struggled in the years after the death of his mother Diana, only seeking help more than a decade later.
Responding to pupils who said they had been talking to each other about the fire, he said: "That's all you can do, is be there for each other because there will be some people... who either don't want to talk about their experiences... or think they are absolutely fine, and in years' time suddenly they might have some nightmares and that's when you guys will be crucial, because you have been through that process."
To one pupil, who said they had felt a "very difficult atmosphere" when they sat an exam after the fire, the prince joked: "Exam conditions are pretty rubbish anyway, I don't think it's changed in the last 20 years."
The brothers were shown around the Support4Grenfell community hub, close to where the charred tower block stands in north Kensington.
The pair were due to be joined by the Duchess of Cambridge but she had to pull out of the visit due to severe morning sickness.