A big rig drove right off a highway Tuesday and hit and killed a maintenance working who was just doing his job. Right now, investigators are working to determine how it all happened.

There is a clear line from the grassy highway shoulder to a water filled ditch -- the path the truck took on Highway 146. A driver who asked not to be identified saw it happen

"I thought he was gonna make that right hand turn," he said. "He just drove down in the ditch and then he tried to get up on the road."

The tragedy is 20-year-old Edson Alaniz Manzano, who working for a state contractor, was mowing the easement and was in the path of the truck. He was killed.

Manzano was employed at Houston-based Biolandscape, which said it couldn't comment on the incident.

Neither could the Indiana-based company that owns the tanker truck, saying an investigation was underway but it expressed its deepest sympathy to the family of the victim.

A lot of people near the accident scene were doing the same, including Genovae Corez, who owns a repair shop just across the street.

"That God give them peace in their lives to be able to deal with this loss," he said.

Two southbound lanes on 146 were closed for a while, but have since reopened.

The driver was identified as 55-year-old Glendall Bickwenhert of Kentucky. Texas City police say he had just left the facility in La Porte en route to Texas City.

Right now, an investigation is underway into what led Bickwenhert to go off the roadway. Police say there were no signs of impairment.