A man has died and his two-year old daughter is in a critical condition after a family of five were swept off rocks and into the sea by a large wave.
It happened at South Fistral Beach in Newquay at 17:20 BST on Friday, the coastguard said.
An RNLI sea scooter was used to rescue the victim's wife while a lifeboat was deployed to recover the man and girl.
Police said two other children managed to get back on to the rocks and were located by the coastguard.
They suffered minor injuries and shock.
'Big, big surf'
The family, from Surrey, were on holiday in the Newquay area.
The father, in his 30s, and two-year old girl were airlifted the Royal Cornwall Hospital in Truro, where he was pronounced dead.
Image copyright APEX Image caption The RNLI sea scooter was used to rescue the victim's wife His wife, also in her 30s, received hospital treatment for minor injuries.
The RNLI said the sea conditions changed considerably between 16:00 and 17:30 and crews were called to three rescues.
James Instance from Falmouth Coastguard said: "At about 16:00 BST, there were normal conditions.
"By 17:00, the swell had picked up to eight to 10ft and that massive increase in such a short period has caught quite a few people unawares."
Image copyright Ken Wilkins Image caption The sea was unusually rough for the time of year Ken Wilkins, who was in nearby Portreath at the time, said the state of the sea was unusual for the time of year.
"Today was the biggest summer swell we'd seen for several years," he said.
"It came up from almost nothing and forced the stoppage of the National Seniors Surf Life Saving Championships."
Police have begun an investigation into what happened and would like to speak to any witnesses who were on the beach.
Det Con Jarrod Yewen said: "This is a tragic incident and our thoughts are with the family at this difficult time."
It happened at South Fistral Beach in Newquay at 17:20 BST on Friday, the coastguard said.
An RNLI sea scooter was used to rescue the victim's wife while a lifeboat was deployed to recover the man and girl.
Police said two other children managed to get back on to the rocks and were located by the coastguard.
They suffered minor injuries and shock.
'Big, big surf'
The family, from Surrey, were on holiday in the Newquay area.
The father, in his 30s, and two-year old girl were airlifted the Royal Cornwall Hospital in Truro, where he was pronounced dead.
Image copyright APEX Image caption The RNLI sea scooter was used to rescue the victim's wife His wife, also in her 30s, received hospital treatment for minor injuries.
The RNLI said the sea conditions changed considerably between 16:00 and 17:30 and crews were called to three rescues.
James Instance from Falmouth Coastguard said: "At about 16:00 BST, there were normal conditions.
"By 17:00, the swell had picked up to eight to 10ft and that massive increase in such a short period has caught quite a few people unawares."
Image copyright Ken Wilkins Image caption The sea was unusually rough for the time of year Ken Wilkins, who was in nearby Portreath at the time, said the state of the sea was unusual for the time of year.
"Today was the biggest summer swell we'd seen for several years," he said.
"It came up from almost nothing and forced the stoppage of the National Seniors Surf Life Saving Championships."
Police have begun an investigation into what happened and would like to speak to any witnesses who were on the beach.
Det Con Jarrod Yewen said: "This is a tragic incident and our thoughts are with the family at this difficult time."
Comment