A young whale that swam aimlessly for two days in a small bay off an industrial section of Brooklyn beached itself at an oil depot dock and died suddenly.

Animal activists said the minke whale, about a year old, was too young to survive on its own.

"It's very sad," said Kim Durham, a rescue specialist at the Long Island-based Riverhead Foundation for Research and Preservation, who had monitored the troubled animal's activities around the clock. "It was a very young whale that became confused and disoriented."

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Earlier, experts had reported seeing nothing to indicate the mammal was sick, such as swimming erratically or in tight circles. With only the whale's dorsal fin visible at times, observers could only guess whether it was injured.

"It would be great if we could say to the whale, 'Say "ahhh" and stick your tongue out,'" said Durham, who had expressed hope earlier that the whale would find its way back into open water in New York harbor. But she said the situation took a bad turn in the early afternoon Wednesday, when the whale's swimming patterns changed.

Durham said a colleague, marine biologist Robert DiGiovanni, was observing the animal when "it suddenly began heavy splashing, hit the dock and then just went quiet."

The whale died about 5 p.m. The end was witnessed by spectators who had been drawn to the dock area in Gowanus Bay by news accounts of the whale.

A police harbor boat secured the whale's carcass, estimated to weigh 3,500 to 5,000 pounds, to the Hess Oil Co. dock, where it was to remain overnight. It was to be towed to an Army Corps of Engineers dock in Jersey City, New Jersey, on Thursday for a necropsy, according to Peter Shugert, a Corps spokesman.

The whale was first spotted on Tuesday in Gowanus Bay, a small estuary off industrial south Brooklyn that is the outlet from the Gowanus canal, a narrow 1.2-mile waterway once lined with coal yards, scrap yards and small industries.