Dozens of whales tragically died on the southwestern tip of Australia in the wee hours of Thursday morning.

Sometime between late Wednesday night and early Thursday morning, more than 150 short-finned pilot whales beached themselves on Hamelin Bay in Western Australia. Piled upon one another, weakly thrashing, they slowly perished before a scatter of saddened onlookers. By 9:30 AM, more than half were dead.

Officials shut down the beach and issued a “shark alert” in order to clear the water. Time was short and with each passing moment, there were fewer left to save. But working with these massive, powerful mammals in unpredictable weather conditions was a risk — not only for the whales but for the people desperately working to save their lives.

“The strength of the animals and the windy and possibly wet weather conditions will affect when and where we attempt to move them out to sea,” said Parks and Wildlife Service Incident Controller Jeremy Chick in an update posted to their site. “The main objectives are to ensure the safety of staff and volunteers as well as the whales’ greatest chance of survival.”

By noon, only 15 whales still lived. Four grueling hours later, just seven. Rocky beach and rough seas sabotaged every effort at an already difficult operation. “The conditions are challenging but we are doing all we can to give these animals the best chance of survival without risking the safety of staff and volunteers,” Chick said.

The rescue efforts sustained another loss before the last six whales were returned to the ocean. Still, questions remain. No one knows exactly why such “mass strandings” take place. Was the dominant whale disoriented, or distracted by the prospect of food? Does the sonar we use for subaquatic mapping and navigation confuse creatures so attuned to its frequencies? We may never know what led to the deaths of these creatures.

Fortunately, for them and for us, there are compassionate heroes willing to step in on their behalf.