An elderly couple from Texas, who vanished while returning home after celebrating Thanksgiving with family, have been discovered deceased in New Mexico.

Gary Lightfoot, aged 82, and Linda Lightfoot were found on Tuesday inside their vehicle, which was located in a field near Tucumcari, as reported by KVII. Authorities suspect that hypothermia was the cause of their deaths.

The Lightfoots departed from their family’s residence in Panhandle, Texas, around 3 p.m. on Thursday, aiming to reach their home in Lubbock, approximately 150 miles away. However, they never arrived, according to CrimeOnline. Concerned family members reported them missing on Friday, prompting the Texas Department of Public Safety to issue a Silver Alert by Sunday.

License plate tracking identified their vehicle in Groom, Texas, and San Jon, New Mexico, while a cell tower in Tucumcari, roughly 140 miles from Panhandle and 180 miles from Lubbock, picked up a signal from their car. These indications suggested that the couple mistakenly took Interstate 40 westward after reaching Amarillo, instead of continuing south on Interstate 27 toward Lubbock.

Efforts to locate the couple included the use of a helicopter by New Mexico State Police, as well as drones and vehicle patrols conducted by the Quay County Sheriff’s Office, according to KVII.