The deep-sea search for six missing passengers of a luxury yacht that sank during a violent storm, including a well-known British technology entrepreneur and his daughter, continued on Tuesday. Divers attempted to search the yacht, which lay on the seabed off the northern coast of Sicily.

But Italian authorities admitted that the chances of finding the missing people alive are diminishing over time.

“We cannot remember situations where people were still alive after 36 or (almost) 48 hours on sunken ships,” said Vincenzo Zagarola, a Porticello coast guard official. It is “difficult to imagine” that people could still be alive in the hull of the yacht underwater, Zagarola said.

So far, only one crew member has been confirmed dead in Monday’s disaster. The body of the yacht’s chef, identified as Canadian-Antiguan Recaldo Thomas, was found during initial salvage operations. 15 people were rescued.

Also missing are British technology entrepreneur Mike Lynch and his teenage daughter Hannah, Morgan Stanley International CEO Jonathan Bloomer and his wife Judy, and lawyer Chris Morvillo, a partner at Clifford Chance in New York who represented Lynch in a recently concluded lawsuit, and his wife Neda.

Lynch, who was charged in the U.S. with fraud related to his 2011 sale of Autonomy to Hewlett-Packard, was acquitted of all charges in June. The voyage on the 183-foot Bayesian, owned by a company controlled by Lynch’s wife, Angela Bacares, was meant to be a celebration of his legal victory, Britain’s Telegraph reported.

Divers resumed work around 8:30 a.m. on Tuesday but had difficulty entering the narrow passages of the crowded wreck, a fire department spokesman said.

Tables and chairs blocked the entrances, cables and lines formed a “kind of mesh network,” spokesman Luca Cari told the Washington Post. “We are currently working on land to plan an intervention and, above all, to create new openings.” The divers searched the stern of the yacht.

Divers have found “no evidence” that any of the missing people are on the ship, he said. However, given the early hour of the sinking, an “operational hypothesis” is that people could still be in their cabins.

Many were apparently caught off guard by the violent weather. Zagarola, a coast guard official, said that only “strong gusts” were expected on the day of the sinking and that no weather warnings had been issued.

One passenger, Charlotte Golunski, told Italian media that she was holding her one-year-old daughter Sophie during the storm.

“I lost my baby in the sea for two seconds,” she told Giornale di Sicilia. “Then I immediately hugged her again in the midst of the angry waves.”

The 185-foot-long, British-flagged Bayesian was carrying 12 passengers and 10 crew about half a mile from the Sicilian fishing village of Porticello when it encountered heavy weather at around 5 a.m. on Monday. Lightning flashed, thunder rumbled and waves battered the ship.

A fisherman described the scene to the Italian news agency ANSA. “It was floating, motionless and suddenly disappeared,” said Pietro Asciutto. “I saw it sink with my own eyes.”

Golunski and her partner, identified by Italian media as James Emslie, had been invited onto the ship as Lynch’s guests. She told Italian newspaper La Repubblica that she had “held her daughter above water with all my strength, stretching my arms up to prevent her from drowning.”

“It was very dark,” she said. “I couldn’t keep my eyes open in the water. I screamed for help, but all I heard around me were the screams of the others.” Eventually, Golunski, Sophie, Emslie and eight others managed to get into an inflatable lifeboat.

The Sir Robert, a Dutch-flagged sailing ship anchored nearby, immediately rushed to the aid of the survivors before the Italian coast guard arrived.

Britain was to send a team of four inspectors to make a preliminary assessment of the disaster.

“We are providing consular assistance to a number of British nationals and their families following an incident in Sicily and are in contact with local authorities,” a Foreign Office spokesman said on Tuesday.

Carl Sputh, a former yacht captain who now works as a broker for Northrop & Johnson, a yacht brokerage firm based in Fort Lauderdale, said sudden weather changes at sea are not uncommon.

“I was a captain for 27 years and I can tell you I’ve experienced waterspouts and microbursts similar to what happened out there that night,” Sputh said in an interview. “You go from zero wind and a beautiful night out of nowhere to 80 to 100 mph winds. And they happen extremely quickly and they’re extremely violent, and then they’re over.”

Yachts like the Bayesian have a retractable keel that helps balance the yacht while sailing and improves stability, Sputh added. The Italian Bayesian was anchored offshore. If the ship planned to move closer to shore soon, Sputh said, it would have been normal to retract the keel to enable navigation in shallower waters.

Bacares, Lynch’s wife, was among the 15 survivors, according to a person familiar with the situation who spoke on condition of anonymity because of the sensitivity of the situation. The Bayesian is owned by Revtom, a company controlled by Bacares and registered in the Isle of Man, records show.

Ayla Ronald, a senior associate at Clifford Chance in London, also survived.

“We are shocked and deeply saddened by this tragic incident,” the company said in a statement on Tuesday. “Our thoughts are with our partner Christopher Morvillo and his wife Neda, who are among the missing.”

“Our top priority is to support the family and our colleague Ayla Ronald, who fortunately survived the incident together with her partner.”

In addition to being chairman of Morgan Stanley International, Bloomer also joined insurance group Hiscox as non-executive chairman last year.

“We are deeply shocked and saddened by this tragic event,” Aki Hussain, the group’s chief executive, said in a statement. “Our thoughts are with all those affected, especially our chairman Jonathan Bloomer and his wife Judy, who are among the missing, and their family as they await further news on this terrible situation.”

Judy Bloomer worked with the British women’s health charity, Eve Appeal.

“Judy is a brilliant advocate for women’s health and medical research and has been an incredible supporter, committee member and trustee of our charity for over 20 years,” CEO Athena Lamnisos said in a statement on Tuesday. “We are deeply shocked to hear the news that our very dear friend and her husband Jonathan are among the missing.”

According to SuperYacht Times, Bayesian was built in 2008 by Italian shipbuilder Perini Navi.

Three diving teams, two from the Italian coast guard and one from the fire department, are involved in the search and rescue operation, the coast guard said.

The yacht sank to a depth of more than 160 feet. The first attempt by the fire department’s cave divers to search the interior of the yacht was unsuccessful, rescue workers said.

On Tuesday evening, Zagarola said that despite the slim chances, it would be “nice” to find the other passengers. “We (are) still looking for missing people.”