Thousands of train passengers could face severe delays until the end of the week - after "extensive" damage to overhead power cables.
The problems at Radlett in Hertfordshire mean services run by three train companies - Southeastern, East Midlands Trains and First Capital Connect (FCC) - are likely to be affected throughout today.
People could be delayed by up to an hour as there's major disruption expected on services between Luton and St Pancras International in London.
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.