PERTH, Australia (AP) — Volunteers worked frantically on a second day Wednesday to save dozens of pilot whales that have stranded themselves on a beach in Western Australia, but more than 50 have already died.

In this photo provided by the Department of Biodiversity, Conservation and Attractions, a pod of long-finned pilot whales gather closely near Cheynes Beach east of Albany, Australia, Tuesday, July 25, 2023, before stranding. Nearly 100 pilot whales stranded themselves on the beach in western Australia and about half had died by Wednesday morning, despite the efforts of wildlife experts and volunteers to save them. (DBCA via AP)

Nearly 100 long-finned pilot whales, stranded themselves Tuesday on the beach by the city of Albany, on the southern tip of Western Australia, south of Perth.

They were first spotted swimming Tuesday morning near Cheynes Beach east of Albany. As the day progressed, the pod began moving closer to the beach, sparking the concern of conservation officers. By 4 p.m., a large stretch of the shoreline was covered in beached whales.

Reece Whitby, Western Australia’s environment minister, said it was particularly frustrating because it’s not known why the phenomenon occurs.

In this photo provided by the Department of Biodiversity, Conservation and Attractions, rescuers tend to a long-finned pilot whales, Wednesday, July 26, 2023, after nearly 100 whales beached themselves at Cheynes Beach east of Albany, Australia. Volunteers worked frantically on a second day to save dozens of pilot whales that have stranded themselves but more than 50 have already died. (DBCA via AP)

“What we’re seeing is utterly heartbreaking and distressing,” he told reporters. “It’s just a terrible, terrible tragedy to see these dead pilot whales on the beach.”

Fifty-two whales had perished, and volunteers are doing what they can to try and save 45 still alive, he said.