A semi-truck rear-ended another semi in the northbound lanes of I-5 around 2 a.m. today, snarling the morning commute for hours near the weigh station by Federal Way.

While the collision resulted in only minor injuries, one of the trucks caught fire, creating a spectacle for motorists, which also contributed to the traffic problems.

“One [truck] was coming from the scale house and the other was already on the mainline,” said Washington State Trooper Karim Boukabou. “The one that caught fire was the cause of the collision. That’s also the one that was cited for a speeding violation.”

Traffic was backed up for miles in the aftermath, with motorists still slowing to look at the smoldering remains of the truck that caught fire as late as 9 a.m.