The plane's two pilots, who apparently fell to the sea, are missing.

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Stanley the white tailed sea eagle has been missing since last Thursday when he flew off during a show at the tourist attraction.

BBC: Warwick Castle bird of prey flies off during display

When the boat docked, he was missing and several hours later his body was found in the sea by fishermen.

BBC: Garry Walton drowning: Family seeks appeal

The four-year-old boy has been missing since he fell from the jetty at Burnham-on-Sea on Sunday evening, prompting a large search operation.

BBC: Dylan Cecil: Sonar team fails to find body off Burnham coast

Seventeen people have been confirmed dead and another 16 still missing since the Costa Concordia struck rocks in the Mediterranean Sea on Jan. 13, triggering an evacuation of more than 4, 000 passengers and crew members.

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Perhaps the closest comparison occurred in 2007, when the MS Sea Diamond ran aground near the Greek island of Santorini, eventually sinking and leaving two passengers missing and presumed dead.

WSJ: Cruise Operators See Shares Fall, Defend Safety

The devices which can help the emergency services track down missing climbers and hillwalkers were previously restricted for use at sea and by aircraft crews.

BBC: Reverse polarity a risk to climbers, mountain body warns