An investigation is under way after a driver died following the collapse of a 27-ton crane into a freezing river.
The crane toppled as the driver, who worked for the Environment Agency, carried out dredging work at Mepal, Cambridgeshire, police said.
Firefighters tried in vain to reach the driver, who was trapped in the submerged cab, said a police spokesman. But he was declared dead around three hours after the crane fell.
"All agencies have worked extremely closely together to make every effort to fully release the man from the water as quickly as possible," said Julian Fountain, incident commander for Cambridgeshire Fire and Rescue Service.
"However, due to the location of the crane, the freezing weather conditions and the fact that the man was trapped, this could not happen in time."
The Environment Agency, which said it had been carrying out "de-silting work" along the river, said it would mount an internal inquiry and co-operate with a Health and Safety Executive (HSE) investigation.
"I, and everyone at the Environment Agency are extremely upset by today's tragic incident. All our thoughts and sympathies are with our colleague's family and friends," said area manager Geoff Brighty.
"We will be mounting a full investigation into the circumstances surrounding the incident and fully co-operating with the Health and Safety Executive (HSE) investigation.
"The Environment Agency had been carrying out de-silting work along the river for the past couple of weeks to manage flood risk in the area."
