Humber coastguard station was alerted
A second man has died in the Teesside area after being caught up during Sunday's storms.
The 61-year old - who had not been named - was running to take shelter in the Berwick Hills area of Middlesbrough.
He collapsed from what is believed to be a heart attack, and the coroner has been informed.
On Sunday a sailor died, and his colleague remains seriously ill, after they were rescued from the sea by Hartlepool lifeboat.
The survivor is recovering in hospital from hypothermia after heavy storms smashed their small boat on Sunday, while they were out on a fishing trip.
Teesside bore the brunt of the day's flash flooding, with emergency services at two hospitals in the region also affected by the storms.
Accident and emergency patients at Middlesbrough General Hospital are having to be diverted to trauma centres in Hartlepool and Newcastle after flood water cut off electrical power.
In neighbouring Stockton-on-Tees, the children's ward of the University Hospital of North Tees has been closed and is likely to remain so for at least a week.
Six lifeboats were called out along the coast during the day and one of them discovered the two men on the fishing trip.
The pair were taken to Hartlepool where one man was declared dead and the other was treated in intensive care at Hartlepool General Hospital.
The men, who were from the Hartlepool area, were thought to have been out fishing for the day.
A spokeswoman for Cleveland Police said: "At approximately 1213 BST today (Sunday) two male casualties were pulled from the sea at Hartlepool Marina.
"It was believed the males were from a boat which capsized at sea.
"Sadly, one of the males has died and the second male is detained at Hartlepool General Hospital. His condition is described as serious but stable.
"Police and coastguard are currently conducting an investigation into this incident."
A spokesman for Humber Coastguard said the boat involved was thought to be a "cobble" or small fishing boat and the accident happened about a mile out to sea.
He said: "Very little is known about it. We are trying to investigate. The boat was in little pieces and fish boxes and everything floating around.
"Life boats and helicopters went out and the Hartlepool lifeboat went out and found wreckage and with the wreckage were two men.
"They were out for the day fishing. The weather caught a lot of people out."