SAN FRANCISCO >> Scientists say a ship may have hit and killed a female humpback whale that washed up at a beach in the San Francisco Bay Area earlier this week.

The 42-foot female whale had four fractured vertebrae, surrounding hemorrhaging and a broken rib leading scientists to their conclusion, said Laura Sherr, Marine Mammal Center spokeswoman.

However, scientists did not find any further broken ribs making a ship strike less definitive, Sherr said. The specific cause of death remains unknown.

“Every whale stranding is an incredible opportunity to learn from these amazing animals and contribute to baseline data,” said Lauren Rust, a research biologist at the mammal center.

The whale was originally thought to be a juvenile but was later confirmed as an adult female.

Fifteen scientists from the mammal center, the California of Academy of Sciences and the University of California, Davis, examined the whale.

The animal was discovered south of San Francisco on Monday, marking the second dead whale to wash ashore in Pacifica since mid-April. It was within sight of the carcass of a 50-foot sperm whale that was discovered dead last month. A cause of death on that whale was not determined.

Scientists say it’s likely a coincidence that this is the second whale stranding in three weeks on the same beach.

Officials say ship strikes are a leading cause of whale deaths, along with entanglement in fishing gear. In California, ship strikes of gray whales are the most commonly reported followed by fin, blue, humpback and sperm whales. When large vessels such as container ships are involved, the ship’s crew may be unaware a strike has occurred. Officials say the number of ship strikes to whales is likely under-reported.

Sue Pemberton a curatorial assistant at California Academy of Sciences, said the examination will enable scientists to make recommendations for slower shipping speeds and route changes that ship captains are now adhering to voluntarily.