The government's advisor on fire and rescue policy - Peter Holland - has been giving evidence today, at the inquest into the Lakanal House tower block fire.
Six people died in the blaze in Camberwell in 2009.
Ronke Phillips has sent this report from Lambeth Town Hall.
More top news
Scotland Yard said the male youths will appear in custody at Westminster Magistrates' Court on Saturday.
The family of Oliver Dearlove urged people to "think again" before using their fists, as the man who killed him began a six-year jail term.
London Fire Brigade took Southwark Council to court on four charges in relation to safety breaches at Lakanal House in Camberwell.