CHICAGO (CBS) — One person is dead after a van went up in flames during a crash outside Chicago’s main post office.

Police said a 1997 Dodge Ram Van was headed east on the 400 block of West Polk Street around 1 a.m. when it hit a concrete wall and burst into flames. The driver as killed instantly.

The victim has not been identified.

The crash happened at the loading dock of the Cardiss Collins Post Office.

The cab of a semi-trailer truck at the scene caught fire after the crash, and was severely damaged. No one was inside at the time.

The Chicago Police Major Accidents Investigation Unit was investigating the cause of the crash.