The most detailed report released so far has the accident in the eastbound lane, east of exit 193 which would be entry to the freeway from old Hwy 320 or Echo Road. Exit 193 is 4.68 miles from 188, the Stanfield exit. This would place the accident about 5 miles east of the Pilot Travel Center off of the Stanfield/Echo exit. The time has been established as 8:15 PM.
The trucking company that Ediberto Carrillo was driving for hasn't been released to the public yet. There are three main potato trucking companies near Hermiston. The truck could have entered I 84 from several exits starting at 177 which connects I 82 to I 84. This is a common route for potato trucks coming from the Plymouth/Patterson farm area. The origin of the haul hasn't been released yet.
All that has been released is the location, time, and that the east bound truck was in the slow lane and the Jetta ran into the back of it. One was killed (by the chute) and two seriously injured. Everything else is speculation. I can't find any info on the two survivors' current condition. The paramedics and law enforcement I know are being very tight-lipped which indicates to me there is an ongoing investigation. We have a trucking company to consider that has insurance and lawyers, we have a commercial driver that may be a factor, and we have three young men and their families to consider.
While rear-ending is considered to be the rear-enders fault, as WF pointed out, most potato trucks aren't well lit from the rear and sometimes very poorly maintained. Also was the chute properly secured? Did the driver have a valid commercial license? Then we must consider if the driver of the Jetta was speeding, perhaps remembering they forgot something needed for the next day's Washington rodeo and turned around. Was he impaired in any way? None of this has been released yet as is common with an accident like this.