Speed and black ice contributed to a large crash on I-84 Saturday night.
7 commercial trucks and 13 passenger cars were involved in a series of crashes.
Nine people were hurt with five people hospitalized in serious condition.
The preliminary investigation revealed speed and black ice were contributing factors creating a domino effect resulting in the multiple vehicle collisions.
Injured persons were transported by Life Flight and ambulance to St. Anthony's Hospital in Pendleton and Kadlec Regional Medical Center, in Richland, WA.