Three men were struck and killed by a pickup early Tuesday crossing a Georgia freeway, causing an 8-mile backup that snarled the morning commute.

Police are trying to determine why the men attempted to walk across Interstate 85, and their identities were not immediately released.

DeKalb County police spokeswoman Mekka Parish says the crash happened around 5 a.m. All southbound lanes of the freeway were blocked for nearly two hours. By 8 a.m., all southbound lanes reopened.

Moments after the crash, two bodies could be seen on the pavement in the two right lanes of the freeway as a DeKalb County police car blocked those lanes. Shortly after that, more police cars and fire trucks arrived and all southbound lanes were closed.

The Associated Press contributed to this report