The Oklahoma Highway Patrol discovered the skeletal remains of six people in two different cars in Foss Lake on Tuesday. Authorities were testing new sonar equipment when they stumbled onto the vehicles in the lake.

Authorities found three bodies in a 1950s Chevrolet model that reportedly belonged to a couple from Canute who disappeared on their way to Foss Lake in the 1960s. The third body had not been identified.

The second car, a 1969 Chevy Camaro, also had three bodies inside. They are believed to be three teenagers who were reported missing from the Sayre area in the early 1970s.

The teens, 16-year-old Jimmy Allen Williams, 18-year-old Thomas Rios and 18-year-old Leah Johnson, were last seen in Williams' blue Camaro on Nov. 20, 1970, which was never found. The three high school friends were going to a football game in Elk City, but may have detoured to go hunting at Foss Lake, according to notes by the National Missing and Unidentified Persons System.