Frantic efforts were made to keep a man alive yesterday when he became trapped by a storm drain as water levels rose.

For four hours police, ambulance and fire crews tried in vain to save the man, named by friends as Michael Barnett.

He was understood to have caught a foot or clothing in the bars of the 6ft-square drain and was unable to escape because of the pressure of water trying to pour through the hole.

As flood waters rose, teams of emergency workers supported his weight against the force of the water to keep his head above the surface, but after several hours in the water he died.

The cause of death was last night unclear but it was suspected that he died from exposure.

“There were crews holding on to him right until the very end,” said Fire Officer Glen Ramsden, who was part of the rescue attempt in Hull.

“There was water rising around him. He was being held by police and fire brigade officers [and]there was a crew giving him oxygen. He was speaking but sadly he has died.”

Firefighters worked to free him by cutting through the bars of the drain covering, which was designed to prevent fallen branches and other debris clogging the drain.

Fast-flowing water was pouring into the drain, which leads to the River Humber, and Mr Barnett and the teams trying to save him were buffeted by rocks swept along by the flood waters draining from fields.

The dead man was understood to have been trying to clear debris from the drain to prevent nearby houses and businesses from flooding.

Mr Ramsden added: “This was an appalling accident. Clearly he was trying to do a favour and became trapped.”

Mr Barnett worked at a fish farm and the owner, Geoffrey Claxon, 76, said that the younger man had been trying to help him and residents of Astral Close, which was faced with rising flood waters.

Mr Claxton said: “Mike was trying to save everything from flooding. He was a big, healthy, strong lad. He would not have been here had he not cared about his job. It is terrible.

“He has worked for me for 11 years; he is like one of the family. He didn’t have to come into work this morning but he did – that is the type of guy he was.”