A narrowboat which sank in a lock, trapping and killing its owner, is thought to have filled with water in less than two minutes, rescue workers have said.
The victim, named locally as Alan Green, is reported to have saved his mother before going back inside his boat in an apparent effort to rescue an amount of cash and other belongings.
Fire crews entered the Droitwich Junction Canal in Worcestershire after the lock was drained and recovered the body of Green, who was pronounced dead.
An air ambulance also attended the scene of the accident - which is not the subject of a police inquiry - at about 11.20am on Monday.
Friends of Green, who was aged in his 40s, said he had lived at a mooring in nearby Droitwich for several years.
His narrowboat, named Sonskit, was removed from the five-year-old lock on Tuesday before being towed to a nearby marina.
Inquiries into the incident may focus on whether part of the 50ft boat, possibly its tiller, became wedged in part of the lock after it was pushed backwards by incoming water.
Speaking after the boat was drained and re-floated by salvage experts, the head rescue coordinator for the River Canal Rescue organisation, Pete Barnett, said the boat probably sank within two minutes.
Asked what caused the accident, Barnett said: "That's down to a full investigation but in my opinion something has got jammed, held the boat down and filled it with water.
"As far as I know the gentleman was very experienced and had lived on the boat for quite a few years."
In a joint statement, Hereford and Worcester Fire Service and West Mercia Police said: "On arrival crews discovered a boat submerged in the water with reports of a casualty still on board.
"Fire crews entered the water and rescued a male in his 40s. Fire and ambulance crews attempted resuscitation, however, in spite of their best efforts, they were unable to save his life.
"Our thoughts are obviously with the family at this difficult time."
The Canal & River Trust, which is responsible for the country's waterways, said it would assist with any investigation to see if any measures were needed to prevent a repeat of the tragic incident.