24 people with minor injuries have been taken to St Thomas' hospital, a London Ambulance Service spokesperson has said.
Several others in a more serious condition are being treated at the scene of the crash.
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Dry with clear spells periods across the south tonight, further north, cloudier conditions bring the chance chance of light showers.
Five-year-old Yusuf Abdismad died from meningitis in January after a mix-up between emergency operators, it has emerged.
A strike by members of four unions, RMT, Aslef, TSSA and Unite, is expected to bring the Underground to a standstill tomorrow evening.