A dead whale that washed up on a San Diego beach has scientists scratching their heads.

The 52-foot female fin whale appeared on Pacific Beach on Sunday morning.

While the whale’s body showed signs of some minor injuries, the cause of death is a mystery.  Researchers do not believe human interaction was a factor.

The fin whale is the second-largest whale species on Earth.

Authorities are planning to tow the whale’s body back out to sea and let it sink.