An oncoming car was unable to slow down in time and slammed into the logs, the Washington State Patrol reported.
State troopers responded to the scene, at I-405 and NE 160th Street, at about 10 a.m.
The driver of the logging truck, a 43-year-old Lynnwood man, and the driver of the oncoming car, a 63-year-old Lake Tapps man, were injured. Both were taken to Evergreen Hospital for treatment.
A preliminary investigation found that the logging truck was heading from 160th Street to northbound I-405 via the entrance ramp when its load shifted. The truck rolled over onto its side, sending logs across the nearest lanes of the freeway.
A 2013 Infinity G37 heading north on I-405 was unable to avoid the logs and slammed into them. The car was totaled and the driver sustained unspecified injuries.
Drugs or alcohol were not a factor in the crash.
The log spill blocked two lanes of traffic and partially blocked the entrance ramp onto to the freeway. A loader was brought in to clean up the mess.
The accident remains under investigation.