How did a truck crash on top of this Houston freeway sign?

When we saw this picture of an empty semi truck trailer crashed into the top of a sign on I-45 in Houston, we probably had the same thought you did. How the hell did this happen? Here's how.

Somehow, the truck's bed's hydraulic arm engaged while driving. Raised up into the air at a nearly 90-degree angle, the empty bed smashed into an overhead beam near the Airline exit, striking a green interstate sign, disengaging itself from the cab of the truck. There the bed sat, seemingly suspended in air, attached to the sign.

Thankfully, the driver wasn't harmed in the late Tuesday afternoon accident. Houston TransStar, the local transportation and emergency management agency, says the driver has no memory of engaging the lifter while on the road.

How did a truck crash on top of this Houston freeway sign?

Houston authorities had to close part of the city's North Freeway while the state cut down the bracing to get the trailer off, leaving hundreds of people stranded in the city's now standard 100-degree heat. The trucking company will have to carry the costs of repairing the damage to the signs, which the state estimates at a cool $100,000.