A badly decayed car found in a south Florida canal may be the key to unlocking the fate of two teenagers who mysteriously disappeared nearly four decades ago, according to the Broward County Sheriff's Office.

The car was discovered by a utility worker on Wednesday and hauled out of the water by the Sunrise Police Department. When they ran its identification number they found it was registered to Harry Wade Atchison III, a 19-year-old who vanished with his 15-year-old girlfriend, Dana Null, on Oct. 7, 1978.

No bodies were found inside the car, Broward Sheriff's Office spokeswoman Veda Coleman-Wright said on Friday.

"I couldn't even recognize it was a vehicle by anything other than its tires," she said. The car is believed to be Atchison's orange 1969 Dodge Coronet.

The two went to a rock concert the night of their disappearance, according to police investigators quoted in a 1995 Sun Sentinel article.

After the show, the pair went back to Atchison's trailer where they got into a fight, the article said. Atchison tried to drive off in the Dodge, but Null stopped him and got into the car. The two were never seen again, it said.

Police reopened the investigation nearly 20 years ago, but failed to find any clues as to the couple's whereabouts, according to the newspaper.

Both Atchison's and Null's parents are deceased, Coleman-Wright said. Each has a surviving sister in Florida but she declined to provide more details.

"Detectives contacted the family and have been focused on the recovery and trying to find any remains," she said.