Cary, N.C. — Daniel Carr, 23, remembers the night his heart began racing uncontrollably. Nearby, his 18-year-old friend Austin Walker experienced similar symptoms, started hallucinating and collapsed on the ground.

The friends were rushed to a hospital after smoking an herbal incense known as K2, and now they want to warn others about the dangers.

“It was possibly the most terrifying experience I’ve ever had,” said Carr.

“It was the worst thing I’ve ever experienced,” added Walker, who says he nearly died.

The friends were at Carr’s parents’ house in Cary last month when they decided to try K2, an herbal product known as man-made marijuana or legal pot, which is legal in North Carolina.

“It’s just an herbal product, so they didn’t see any harm in it, and what happened the rest of the night was a nightmare for everybody,” said Cindy Carr, Daniel’s mother.

Tim Carr held his son’s friend after the teen collapsed near the back deck.

“I had to literally sit with him and hold tight. I mean, he was so tense, you know. It was almost cutting off my circulation,” Tim Carr said.

The Carr family said they don’t want this to happen to anyone else.

The K2 product goes by various names, including spice and black mamba, and is sold at several area smoke shops and convenience stores. It has similar properties to the THC in marijuana and comes with a disclaimer: “Not for human consumption.”

A local couple, who did not want to be identified, said they and many of their friends have smoked K2. One of those friends was rushed to Rex Hospital and died Saturday night, they said.

“It basically feels like your heart is beating 10 million miles an hour,” said the anonymous couple. “I would say out of the 20 people (whom) I talked to since 7:30 yesterday, 17 had said that they had tried it or one of their friends had tried it.”

Those who've had frightening experiences with the product are urging lawmakers to take a closer look, and some lawmakers have already talked about banning the product.

“It should not be (legal), absolutely not. It boggles my mind that it still is,” Carr said. “This is far deadlier than anything that I have ever experienced.”

WRALNews tried to get a response Sunday night from a shop owner who sells K2. The man, who did not want to be identified, said he has heard too many bad things about K2 and is pulling it from his shelves.

John Huffman, a Clemson University chemist who developed the product while doing pharmaceutical research, said last month that the research did not shed any light on the safety of the product and that he is not responsible for its recreational use.