DALLAS (CBSDFW.COM) – A pedestrian is dead after being hit be a semi tractor-trailer along Interstate-35E in the Oak Cliff area of Dallas.

The accident happened around 1:00 a.m. Friday in the southbound lanes of the highway, near Loop 12.

All of the southbound lanes of the intestate were closed for more than three hours while police investigated.

Officials haven’t said why the man was on the highway. It isn’t known if the driver of the big rig was injured.

The name of the victim has not been released.