PACIFICA, Calif. (AP) – Scientists are at San Francisco Bay Area beach Wednesday attempting to determine what killed a beached humpback whale.

The necropsy started Wednesday morning. There was some concern late Tuesday that the carcass was being dragged to sea by waves.

The 32-foot female whale was discovered south of San Francisco Tuesday, marking the second dead whale to wash ashore there since mid-April.

It was within sight of the carcass of a sperm whale that was discovered dead last month.

This is the third dead whale found in the San Francisco Bay Area this year.

Last month, a 50-foot sperm whale washed ashore at the same beach in Pacifica.

In January, a rare pygmy sperm whale died after beaching itself in Marin County. Investigators said it had likely gotten sick and was too weak to swim.