Several sperm whales have been found dead near Ardrossan, Australia, in a rare mass beaching, according to reports.

Six were discovered on shore Monday, and a seventh was spotted several kilometers away. According to the Advertiser in Adelaide, an eighth whale was at risk of being stranded but was ushered into deeper waters by marine officials.

Dr. Deborah Kelly, an animal welfare manager on the case, called the beaching "rare" and "horrific," the outlet notes. She theorized that the whales either were feeding too close to shore and couldn't return out to sea or came to the aid of a sick whale in shallow water and got stuck there. "We'll probably never know," she said.

Sperm whales can measure between 49 and 59 feet long and weigh between 35 and 45 tons, according to National Geographic.

The spectacle of the leviathans on the sand attracted the curious -- and the larcenous. Some of the whales' valuable teeth were stolen overnight, prompting government officials to announce a fine of up to $100,000 for anyone coming within 50 meters of the carcasses, the Advertiser reported in a follow-up piece. Disease and the possibility of the carcasses exploding were also noted as reasons to keep onlookers away.