Detective Chief Inspector Dick Pearson said: "These deaths are being treated as unexplained. The full circumstances of this tragic work-related incident are being investigated by the police with the assistance of the Health and Safety Executive."
More top news
A GP in Surrey has launched a petition calling for a £90m fine handed to two drugs companies, to be reinvested in the NHS and epilepsy care.
Friday evening's weather update for the east
Friday evening's weather update for the west