The young, 18-foot female orca was first spotted close to the coast of Cadzand, Zeeland, at about 4:30 p.m. Sunday, Annemarie van den Berg, director of the SOS Dolfijn foundation, a rescue organization, told Newsweek.

Rescuers from SOS Dolfijn and KNRM Cadzand initiated efforts to refloat the orca, which had entered the surf. SOS Dolfijn said in a Facebook post that to see an orca so close to the shore was worrying.

Orcas, also known as killer whales, can be found in waters worldwide. They occasionally enter the North Sea, but it is extremely rare to see one in the Netherlands.

Rescuers managed to face the orca back toward the direction of the sea, and for a while it disappeared.

However, just two hours later the orca had stranded 1.9 miles away from where it was initially sighted. As the tide was going down, making refloating efforts even more difficult, rescuers initiated an urgent medical examination to determine how best to help the stranded whale.

Marine mammals can strand for a number of reasons. When whales are sick or injured they can become disoriented and end up trapped in shallow areas.

“Since the animal re-stranded, a thorough medical check was necessary,” van den Berg said. “Therefore, our rescue team and a specialized veterinarian went to the stranding location. It was a few hours’ drive, and in the meantime the local fire department and us trained volunteers took care of the animal, by keeping the orca wet and humans at a safe distance. The medical examination showed that the female orca was not in good condition.”

Rescuers decided the best way forward was to euthanize the whale, but as they prepared to do this, it died, van den Berg said.

Orcas usually travel in pods. They are highly social creatures, so seeing one away from its pod is rare. Rescuers did not see any other orcas.

It is also rare to see them so close to shore. As this orca was young and away from its pod, it was particularly vulnerable.

The nonprofit Orca Rescues Foundation said in a Facebook post that the incident was “a sobering reminder that wild orca face some serious, life threatening challenges out there.”

Scientists are done an autopsy of the whale to determine the cause of death, which could be “many things,” according to the Orca Rescues Foundation.

“She was notably thin. It is not uncommon for wild orca to carry a pollutant load of [man-made chemicals] and other foreign chemicals in their bodies as a result of being high on the food chain,” the charity’s Facebook post said. “The fitter and healthier they are, the more they’re able to fight off its hazardous effects, but they’re not exempt from illness, side effects, or death, brought on by repeated, high exposure.”