Groton — State police said 41-year-old Mayro A. Estrada of Providence, R.I., died when the tractor-trailer he was driving south on Interstate 95 left the roadway and crashed into an embankment Tuesday morning.

Police said Estrada's tractor-trailer, owned by RTS Holdings LLC of Randolph, Mass., went off the left side of the road just north of Exit 89 about 4:53 a.m.

The truck traveled through a guardrail and down a hill, hitting an unoccupied hydraulic lift and crossing Cow Hill Road before crashing into a dirt embankment.

Police said Estrada, pronounced dead on scene, was not wearing a seat belt.

The crash, which is under investigation, closed Cow Hill Road for several hours and prompted repair work on the I-95 guardrail and nearby power lines.

RTS Holdings, which does business as RoadOne IntermodaLogistics, says on its website that it has more than 1,700 vehicles and drivers and has access to warehousing, distribution and loading space at more than 100 locations in the United States and Canada.