PALERMO, Italy – One man died and six people were missing, including British tech entrepreneur Mike Lynch and his daughter, after a luxury yacht was struck by an unexpectedly violent storm and sank off Sicily early on Monday. The British-flagged “Bayesian”, a 56-metre-long (184-ft) sailboat, was carrying 22 people and was anchored just off shore near the port of Porticello when it was hit by ferocious weather, the Italian coast guard said in a statement. Eyewitnesses said the yacht vanished quickly beneath the waves shortly before dawn.

Fifteen people escaped before it went down, including Lynch’s wife, Angela Bacares, who owned the boat, and a one-year-old girl. The names of the dead and missing were not immediately released, but a person familiar with the rescue operation confirmed that Lynch and his 18-year-old daughter, Hannah, were not accounted for. Italian media said the dead man was the yacht’s onboard chef.

The Italian coast guard said the missing had British, American and Canadian nationalities. Survivors said the trip had been organised by Lynch for his work colleagues. “The wind was very strong.

Bad weather was expected, but not of this magnitude,” a coast guard official in the Sicilian capital Palermo told Reuters. The captain of a nearby boat told Reuters that when the winds surged, he had turned on the engine to keep control of his vessel and avoid a collision with the Bayesian, which had been anchored alongside him. “We managed to keep the ship.