Interstate traffic is still snarled in western Iowa after two semis collided and caught fire about 5:30 this morning, killing one truck driver. Traffic on I-80 is being re-routed as both westbound lanes are still closed at milemarker 80 between Casey and Adair. Highway Patrol Sergeant Rob Hansen says one truck rear-ended another and ended up in the ditch. Both eastbound lanes are open, but Hansen says westbound traffic is backed up for miles. Hansen expects the traffic delays to last through the morning.Hansen couldn’t say what either truck carried. No names have been released.