(CBS) -- The families of missing teens Jake Ziegler, 18, and Ray Pierce, 17, have hired a private investigator to work with them to find their sons, CBS affiliate WBTV reports.
The teens have been missing since Oct. 13 when family members believe that they were headed to Myrtle Beach, S.C. There is no evidence that the high school seniors from Sherrills Ford, N.C. ever arrived at their destination. Neither their cell phones nor their debit cards have been used since.
"We just need that next piece to give us another direction," said investigator Kevin Ryan. He does not believe the boys ran away or were abducted.
Fairfield County Chief Deputy Keith Lewis said last week that all information investigators have collected leads them to believe that the teens crashed along interstate 77, trapping them in their car. If the crash did happen, Lewis believes it would have occurred near mile marker 48. Ziegler and Pierce were driving in a green Pontiac, which could make it difficult to spot the vehicle.
The search for the boys is now focused on Interstate 77. This is where authorities say that Ziegler last used his cell phone to send a text message at about 2:45 a.m. on Oct. 13. On Tuesday morning, agents from South Carolina's Law Enforcement Division (SLED) searched for the teens near Great Falls in Chester County, WBTV reports.
The last text sent from one of the boy's phones said, "We're almost at the beach." Investigators, however, don't think that the boys ever made it that far.
"It's tough to eat, it's tough to sleep, if you're sleeping, it's tough to get yourself up the next day and get going again," Zig Ziegler, Jake's father, said.
Family members have said they have reason to believe that the teens may be in Conway but will not release the information that led them to that conclusion.
"My son doesn't have much longer, if he's alive. I believe he is," said Zig Ziegler.