MCMINN COUNTY, TN. (WRCB)-- New details in the McMinn County car crash that claimed four lives.

The crash happened just after 1 PM.

According to the Tennessee Highway Patrol, 20-year-old Christan Wagner was driving eastbound in a 1996 Dodge Neon when she crossed the center lane and hit a Wal-mart truck head-on.

Investigators on scene told Channel 3 Eyewitness News the truck began leaking diesel causing a fire. The fire destroyed the cab but did not burn the car.

Investigators believe Wagner and the three passengers, 25-year-old Michael Shell, 2-year-old Michael Shell Jr., and 11-month-old Adrian Damien Shell were killed on impact.

Wagner was pregnant, but the fetus will not be counted as a 5th fatality.

Lt. Daniel Ruskey told our partners at the Times Free Press, "This is probably one of the worst [crashes] I've been involved with in 15 years with the Highway Patrol."

The driver of the Wal-mart truck was not injured and will likely not face charges.

All four killed were from Madisonville, Tennessee.