A 15-foot-long pilot whale beached itself Thursday morning on Hilton Head Island and died, causing a stir for beachgoers, some of whom tried unsuccessfully to save the mammal.

A necropsy performed on the whale, found near the heel of the island at Port Royal Plantation, did not reveal a cause of death. More tests to check for viruses or other conditions that led to the 700-pound mammal's stranding will be completed in coming weeks, said Jessica Conway, a marine mammal technician with the National Oceanic and Atmospheric Association.

It was the first pilot whale to be stranded on Beaufort County shores since 2012, when one was found on Hunting Island.

The whale on Hilton Head was found near marker 118 at about 6 a.m. by a beachgoer who notified the Beaufort County Sheriff's Office.

A group of about eight people tried to push the dying whale back into the water, according to an email to The Island Packet from an onlooker. The whale had been thrashing in the surf, but was dead by 7:30 a.m. when volunteers with the island's Sea Turtle Protection Project arrived.

Conway said it's never a good idea to try to handle stranded mammals because of the possibility of injury to would-be rescuers. Pushing a whale back into the water likely won't prevent it from stranding itself again, she said.

On vacation from Colorado, Christine Torres and her daughter rode their bikes by the whale at about 1 p.m. before stopping to try to find out what happened and to see what they could do to help.

"We were concerned," she said. "My immediate response was, 'Is it savable?' Now I know not to get near it."

While waiting for NOAA marine mammal specialists to arrive, town employee Terry Overland used a winch attached to a pickup truck to move the dead whale about 20 feet up the beach. NOAA representatives arrived soon after noon to begin the necropsy, an animal autopsy. Low tide was at 12:45 p.m.

The necropsy took about three hours. Conway said there were no apparent physical injuries, and tissue samples would be tested over the next few weeks.

It was unlikely the whale was affected by the morbillivirus, which has killed hundreds of dolphins and some whales along the East Coast, she said, but testing would confirm that.

Pilot whales are social mammals that usually live in groups of 20 to 200. The species is known for group strandings, in which one dies and others follow.

A crew from Port Royal Plantation brought a backhoe onto the beach around 3 p.m., burying the whale next to the area where the necropsy was performed.

Between the time the NOAA team arrived and the whale was buried, a steady crowd gathered. One group of teenage girls even took a photo of themselves with the carcass in the background, after the NOAA specialists had removed the whale's head for further study.

Many onlookers asked questions and also took pictures of the whale, including Hayley Thompson. On vacation at the nearby Westin Resort from Kentucky, Thompson was both intrigued and horrified by the necropsy.

"It was pretty gross, but it was cool," she said.