Two men are dead this morning after a pickup truck crossed the median on Interstate 10 in Casa Grande, Arizona, and struck a semi truck head-on.

The incident occurred around 5 a.m. in the morning, near mile marker 186. The impact killed both the driver of the pickup truck and the driver of the semi truck.

The semi truck was hauling milk and was traveling on the eastbound lanes.

According to ABC-15, an investigation is underway to determine why the pickup truck drifted into opposing traffic.

The drivers’ names have not been released.

Eastbound travel was restricted to one lane for several hours after the crash, backing up traffic for about a mile. The lanes have since been reopened.

This post will be updated as more information is made available.