Five sperm whales that beached on a Dutch island have died before anyone could attempt a rescue operation.

The whales, ranging in size from around eight to 12 meters (25-40 feet) were first spotted stranded on a beach on the island of Texel on Tuesday. A museum and wildlife center on the island, Ecomare, says that experts who studied the marine mammals early Wednesday confirmed that all five were dead.

It was not clear why the whales beached themselves on the island 100 kilometers (60 miles) north of Amsterdam. Texel is one of a string of islands in the shallow Wadden Sea off the Dutch coast.

In 2012, a 12-meter humpback whale got stuck on a sandbank near the coastal town of Den Helder, close to Texel, and died despite efforts to save the animal.