Mountainburg, Ark. ? A Kansas truck driver hauling hogs was killed when his rig ran off Interstate 540 and struck a concrete bridge pillar. Hogs escaped from the truck and blocked traffic before being herded into a makeshift pen.

State police identified the dead man as Armin Brandhorst, 34, of Green, Kan., which is northwest of Manhattan. Troopers speculated that Brandhorst may have fallen asleep, then overcorrected after waking to realize his rig was leaving the roadway.

“We had about 40 hogs all over 540 highway,” wrecker service owner Ken Pence said. Some hogs remained trapped in the trailer and had to be lifted out with straps and a front-end loader.

Brandhorst was hauling 90 hogs to Little Rock. State police said about 20 were killed in the Thursday morning wreck.