(KMOV) -- A man is dead following a wrong-way crash in south St. Louis County.
It happened around 3:00 a.m. on Friday on Interstate 55 near the I-270.
Investigators say the man was driving north in the southbound lanes when he crashed into a tractor-trailer.
Several lanes were shut down.
The victim was a 20-year-old man from Arizona. His name has not yet been released.
The driver of the tractor-trailer was not hurt.
Investigators are not sure why the victim was driving the wrong-way.