OKLAHOMA CITY -- Authorities are warning people about a heart stopping scam that plays on the basest human fears and could cost thousands of dollars.

Oklahoma State Troopers told KOCO-TV that said someone is calling people to tell them someone they know has been involved in a crash and they must call another number for more information.

"I know my heart was racing. I know my mom's heart was racing," said Linda Lerma, who received one of the calls. "They said it was fatal, which is telling me maybe somebody's dead."

Lerma said the caller claimed to be with the Oklahoma Highway Patrol and told her to dial the number of a sergeant at the scene of a crash.

"This is the sickest kind of sick," said OHP Capt. Chris West. He said the phone call is designed to trick the recipient into paying for other people's calls.

The number, troopers said, begins with the prefix Star 72, which prompts the phone company to forward calls to the number entered.

West said troopers never inform you of a loved one's death over the phone. They always deliver the unfortunate message in person.

"When you've actually gone to people's houses and knocked on the door and woke them up in the middle of the night to deliver these death messages. I mean -- myself -- as a law enforcement officer, I take this kind of thing personally," West said.

"To intentionally try to scare somebody is not nice," Lermas said. She said she didn't dial the number and was ready when the same scammer tried to do it again on Thursday.

"This guy's not very smart that's doing it because he called me back again today and went on to tell me the same story," she said.