A record 129 common dolphins have stranded themselves over three weeks along the coast of Cape Cod, Massachusetts.
A marine mammal specialist told CNN on Monday it was the Northeast's largest "single-species event" of its kind on record.
The New York Times reports that while this isn't a new problem, most strandings end within two days -- this time it has carried on for almost a month with no end in sight.
MSNBC reports the dolphins oddly seem to be healthy. While common dolphins are "known to strand in groups due to their tight social structure," the unusually large numbers have prompted investigation of factors such as tides and weather.
According to the Boston Herald, the International Fund for Animal Welfare has rescued and released 37 of the dolphins stranded between the 25 miles of beach. The other 92 animals were either dead or euthanized when staff responded.
The rescued dolphins are checked, tested and tagged with an identifier before release, Reuters reports.
On the other side of the world, a mass stranding of whales recently occurred in New Zealand. The Associated Press reported that nearly 100 pilot whales stranded themselves on January 23.
Check out the slideshow below to view some of the most bizarre mass animal deaths throughout history: