A collision on eastbound Interstate 90 early Wednesday left one car overturned on the freeway, blocking all but one lane and causing significant traffic backups that persisted even after the road reopened.

The collision occurred around 6 a.m. east of West Mercer Way, according to the Washington State Department of Transportation.

On Twitter, the Seattle Fire Department said firefighters were responding to the crash, and encouraged drivers to avoid the area.

The crash was cleared and lanes were reopened by 8 a.m., but drivers were urged to use Highway 520 as an alternate route across Lake Washington.