A collision involving a dump truck during the morning commute today on southbound Interstate 405 backed up traffic about seven miles, all the way to Interstate 90, according to the Washington State Patrol.

The dump truck was pulling a small backhoe on a flat-bed trailer, according to Trooper Dan McDonald. The trailer “started whipping” when the truck slowed, hitting both jersey barriers, he said.

A southbound car then hit the dump truck, he said.

A passenger in the car was taken to a hospital as a precaution, McDonald said. There were no other injuries.

McDonald said the dump truck’s speed was a factor, as well as the fact the load wasn’t properly distributed in the truck and trailer.

Southbound travelers bypassed through Renton and traffic was allowed to detour through the I-405 construction zone for a time, according to McDonald.