HOUSTON (KIAH) — Investigators are trying to figure out why a man was standing in the middle of a lane of Highway 6 before an Amazon tractor trailer hit and killed him.

It happened around 3:40 a.m. Monday between Richmond and Westpark.

Houston Police say the man was pronounced dead at the scene.

They also say the truck driver stayed at the accident scene and is cooperating with them.

The highway was closed while police investigated the incident, but it is back open.