The workman killed at Langley Green Primary School has been named today (October 10).
The man has been identified as Daniel Clifford Yeowell, of Albany Road, Gillingham, Kent.
The 26-year-old suffered a serious head injury believed to have been caused by a manhole cover falling onto his head.
He was taken by air ambulance to the Royal London Hospital in East London but died there on Monday (October 7).
The incident took place on a building site in the grounds of Langley Green Primary School.
Mr Yeowell is understood to have been working in a hole.
Police and the Health and Safety Executive are working together to investigate the circumstances.
An inquest into Mr Yeowell's death is yet to be opened.