Morning pile-up on I-5 caused by distracted drivers, troopers say (VIDEO)

SEATTLE — A huge traffic pileup that blocked all northbound lanes of Interstate 5 near the Washington State Convention Center Tuesday morning was caused by distracted driving, Washington State Patrol troopers said.

Trooper Chris Webb said a driver had dropped his cell phone, went down to pick it up, and didn't realize the traffic had stopped until he looked back up. Webb said the driver wasn't able to stop in time and crashed into a car in front of him, causing that car to hit others.

"He shouldn't have had a phone in his hands in the first place," said Trooper Webb.

Webb said the impact of the initial crash was so severe, the initial pick-up truck that started the crash ignited into flames.

"When you’re driving, you have to be attentive to what’s going on around you," said Webb.  "It’s a multitask-type job, so when people start veering away from what they’re doing-things like this happen."

WSDOT first tweeted about the traffic backup around 8 a.m. Tuesday . At 8:37 a.m., all traffic was forced off at Olive Way, and the traffic grew to a 7-mile backup on I-5.  By 10 a.m., WSDOT said three lanes of Interstate 5 through downtown Seattle reopened, but traffic delays were omnipresent across the region.

The Washington State Patrol reports the Tuesday morning accident sparked a truck fire. Emergency personnel were on the scene and there were reports of injuries. Distracted driving was involved, troopers said.

Transportation officials still advised drivers to use alternate routes early in the afternoon.