A Portage bicyclist was killed on Thursday after being struck by a semi in the 900 block of North Ind. 149, the Porter County Sheriff’s Police said.

The victim was identified as Douglas Ewing, 31. He was pronounced dead at the scene.

Coroner Robert Schulte told the Chesterton Tribune today that an autopsy has been performed and that Ewing died of massive blunt force trauma to the head and abdomen, including a lacerated liver.

According to police, at 6:39 p.m. Ewing was southbound on Ind. 149—wearing dark clothing and with no reflectors on the bike—when he weaved into the traveled portion of the roadway and directly in front of a southbound semi-tractor trailer, driven by Brandon Griffith, 50, of Hobart, who was unable to avoid hitting Ewing.

Ewing—who was not wearing a helmet—was thrown into a ditch, Schulte said.

Police said that Griffith tested negative for alcohol in a routine test.

Ewing was last seen by a family member when his brother dropped him at a friend’s house, Schulte said, and the family was unable to say whose bike Ewing was riding.

Schulte, who noted that there had been an anonymous report earlier of a bicyclist seen weaving on Ind. 149, said that he believes “toxicology will play a major role in this accident.”

Results from the tox screen are pending.