A man from Brighton suffered serious chest injuries at the Lewes Bonfire event last night.
The 21-year-old was struck by a rocket and suffered serious burns to his chest.
The man, a member of the Commercial Square Bonfire Society, was hit by the stray firework during the display at Landport recreation ground in Lewes.
He is being treated for his internal injuries at the Royal Sussex County Hospital in Brighton.
His condition was described as critical but stable.
Sussex Police said that it would liaise with Lewes District Council and the Health and Safety Executive to establish what had happened.
