It was a scary moment for an Oklahoma truck driver Sunday afternoon when his semi-truck crashed through the wall of the National Guard Armory on U.S. Highway 80.

The crashed happened around 3 p.m. Sunday when the truck Stephen Wayne Maynard, 46, was driving veered off the road, went through cement barricades and went through the wall of a conference room at the armory. The truck was carrying building materials.  According to Alabama State Trooper Reginal King, Maynard was not injured in the accident, but he was airlifted to Baptist South in Montgomery for observation.

It is unclear what caused the truck to go off the road and crash into the building. A large hole in the building was boarded up Monday afternoon. There were still other signs of the crash with black tire streaks across the lawn in front of the building and oil in the parking lot

King said the truck was traveling eastbound, but it is still unclear how the accident happened. The crash is still under investigation by Alabama State Troopers.

The Alabama National Guard Public Affairs Office did not return phone calls Monday. It is unclear how much damage was done to the building or if anyone was inside at the time of the crash.

Units stationed at the armory are the 440th Transportation Detachment and the 122nd Troop Support Command.

No one with the armory could be reached Monday for comment.