Mr Barnett had cleared debris from the same drain in an earlier flood

Geoffrey Claxton, 76, told the inquest into the death of Michael Barnett on 25 June he saw divers, 999 crews and residents trying to save the man.

Mr Claxton's family owns the tropical fish business where Mr Barnett worked.

Mr Barnett, 28, was tangled in metal fencing used as a temporary grille on a storm drain as the floods rose.

He died from hypothermia after an unsuccessful four-hour operation to free him from the neck-high floods.

Geoffrey Claxton said everyone was trying their best but "there wasn't any organisation as far as I could see".

He told the inquest at the Goodwin Centre in Hull that at one point Mr Barnett went completely under the water as rescuers tried to pull the grille free using the winch on a Land Rover vehicle.

Divers managed to bring the trapped man back above the water, which Mr Claxton said was "unbelievable, like Niagara Falls".

Mr Claxton said residents from nearby Astral Close were joining in the operation, with one man standing on a nearby garage holding a rope.

Flooding in Howdale Road, Sutton in Hull

He described how he had been in the floodwaters earlier, but became cold and exhausted.

"Everyone was doing what they could to get him out.

"He was visibly shaking with the cold. He wasn't saying much by then."

Mr Claxton added: "There wasn't any organisation as far as I could see.

"Everyone was doing what they could, I suppose, but they didn't seem very professional. Nobody seemed to know what to do.

"I couldn't understand why they couldn't have put a harness on him and pulled him out.

"One of the tragedies for me that I can't still get over is the fact that Sea King [helicopter] flew over us and I felt I could just jump up and catch it."

The culvert had been protected by a steel box, but this had been removed by a digger during the flooding 10 days earlier and replaced by the grill.

The inquest continues.