Two years after a 3-year-old endangered orca washed ashore in southwest Washington, investigators have concluded that the whale was hit, struck or rammed in the head and neck. But they couldn't determine the source of that blow.
In a report released Tuesday, the team of biologists and veterinarians ruled out possible sources of the blunt trauma, including sonar and small underwater explosive activity in Canadian waters off Vancouver Island.
The death investigation found that the orca known as L-112 likely died miles south of there, somewhere between north and central Oregon.
The report by the Northwest Marine Mammal Stranding Network also notes that no U.S. naval training activities involving sonar or explosives were conducted in the area during the time of the whale's death in early February 2012.
Some whale advocates had raised suspicions that the orca's injuries were linked to an underwater explosion or military training activity at sea.