10:10 a.m. update: All lanes reopened to traffic.
9:40 a.m. update: The three left lanes remain blocked. The backup is growing to four miles.
9:30 a.m. update: Tow has arrived on scene. The backup is two miles and growing.
A rollover collision is blocking the three left lanes of southbound I-5 at 164th St. SW. Fire and State Patrol are on the scene. Traffic is backed up to 128th.