Video: 9 Hurt In Series Of Chain-Reaction Crashes

Nine people were taken to hospitals, but none was seriously hurt.

Investigtors say the crashes occurred when a wave of rain and sleet blew through the area and a couple of vehicles slid.

Drivers were going about 70 miles per hour in the rain, which was too fast for the conditions and there was no time to stop, troopers said.

After a major backup, northbound Interstate 5 was closed from about 2:30 p.m. until 4:50 p.m. before being reopened.

Washington State Patrol Trooper Bob Wilson said Sunday's I-5 accidents serve as a reminder that winter weather brings freezing conditions to the roadway, including snow, slush and black ice.

"Watch especially for black ice, because as soon as you put on the brakes, there's no way to steer," he said.