Officials said alcohol may have played a factor in a massive crash on Interstate 65 southbound overnight.
The incident happened around 12:15 a.m. Monday at mile marker 104 in Robertson County.
Officers said a pickup truck rear-ended a semi that was stalled on the shoulder waiting for a tow truck.
The driver of the semi wasn't injured, but the driver of the pickup was flown to Vanderbilt University Medical Center with head injuries.
The roadway was closed for a few hours but has since reopened.
Officers said alcohol may have played a factor in the crash, but an investigation was still ongoing.
The identities of the victims have not been released.