Divers are searching off the Italian island of Sicily for six people missing after a superyacht sank during a sudden storm, killing at least one person, officials said.
The 56-metre-long luxury yacht had been moored off Porticello, east of Palermo, when violent winds and rains swept suddenly up the coast before dawn, tearing through beach clubs and fishing ports.
The missing people were of British, American and Canadian nationality, the coast guard said.
British technology tycoon Mike Lynch is reportedly among those missing. Mr Lynch was born to a Co Tipperary mother who was a nurse and a Co Cork father who was a firefighter.
The captain of a nearby boat told Reuters that when the storm hit he turned the engine on to keep control of the vessel and avoid a collision with the Bayesian.
"We managed to keep the ship in position and after the storm was over, we noticed that the ship behind us was gone," Karsten Borner told journalists.
He said that his crew then found some of the survivors on a life raft, including three who were seriously injured and took them on board before the coast guard picked them up.
Cpt Borner said "a little baby and the wife of the owner" were among the survivors, while the owner of the sunken ship and another child were among those missing.
Who is Mike Lynch, the tech tycoon missing off the coast of Italy?
Among the 15 survivors were an Irish national, two people with joint French and British nationalities, a Sri Lankan, and a New Zealander, according to media reports.
"It was terrible. The boat was hit by really strong wind and shortly after it went down," a British survivor called Charlotte told ANSA news agency.
The Bayesian, flying the British flag, had 22 people aboard, including ten crew members, the coast guard said. The majority of those aboard were British, according to Italian media.
Charlotte said her young daughter had nearly drowned.
"For two seconds I lost her in the sea, then I grabbed her again. I held her tightly to me, while the sea raged. Lots of people were screaming," she was quoted as saying.
She managed to climb aboard a lifeboat, she said.
The yacht was anchored some 700m from the Porticello port when it was struck by a waterspout, which roughly resembles a mini tornado over a body of water.
"I saw the boat, it just had one mast, it was really big. I saw it suddenly sink," fisherman Pietro Asciutto told Ansa news agency.
Another witness cited by Ansa said, "The boat was all lit up. Around 4.30am, it was no longer there. A beautiful boat where there was a party. A normal joyous vacation day at sea turned into tragedy."
Another yacht in the vicinity provided help until rescuers arrived, media reports said.
Fisherman Fabio Cefalu said he and other fishermen rushed to the yacht's help too.
"But we didn't find anyone in the sea, we only found cushions and the remains of the boat," he said.
Just a few hours later, the seas were calm as rescue divers recovered a body from the area the yacht went down.
Emergency services were spotted carrying a body bag to shore.
Camper & Nicholsons, the managers of the yacht, said in a statement that they were "assisting with the ongoing search" for the missing people.
Italian authorities have opened an investigation into the incident.
The Bayesian was a luxury superyacht built by the Italian shipbuilding firm Perini Navi in 2008.
It had an 11.51m mast and could reach speeds of up to 15.5 knots, according to the Boat International website.
A waterspout is a column that descends from a cloud to form a rotating mixture of wind and water over a body of water, often during severe thunderstorms, according to National Geographic.
"The wind was very strong. Bad weather was expected, but not of this magnitude," a coast guard official in Palermo said.
Storms and heavy rainfall have swept down Italy in recent days - with floods and landslides causing major damage in the north of the country - after weeks of scorching heat.
Ireland's Department of Foreign Affairs said it is aware of the incident and is providing consular assistance.
The 15 people rescued are all in stable condition, Adnkronos news agency said.
Eight of those rescued, including the one-year-old girl, were transferred to local hospitals and were all in a stable condition, local media reported.
The boat left the Sicilian port of Milazzo on 14 August and was last tracked east of Palermo yesterday evening, with a navigation status of "at anchor", according to vessel tracking app Vesselfinder.
