Four Mississippi residents were killed in a crash on Interstate 12 in Livingston Parish on Thursday morning, according to Louisiana State Police.

The accident happened around 5 a.m. Louisiana State Police said Willie Smith Jr., 57, of Loranger, was driving west on I-12 in 1998 Lincoln Town Car at the same time a Mississippi man and his three passengers were driving east in a 2010 Nissan Altima.

Authorities said, for unknown reasons, Smith crossed the median and struck the other car head-on.

All four Mississippi residents were unrestrained and died at the scene, State Police said. Smith is at an area hospital with serious injuries; he was wearing a seat belt.

It's unclear if impairment played a factor in the crash. Toxicology samples were taken from both drivers.

Eastbound I-12 was closed for about two hours Thursday morning.