The highway will remain closed through Monday night as workers continue to remove the wreckage. Now they're aiming to reopen the road at 5 a.m. Tuesday.

The big rigs ran head-on into each other as they passed beneath the overpass under construction at the Maple Valley Highway interchange. Both trucks caught fire, trapping the drivers inside.

State Transportation Department spokeswoman Claudia Cornish says the collision and fire damaged temporary supports on the South East 231st Street bridge. The bridge was under construction to widen Highway 18 from two lanes to four. Cornish says the highway and the South East 231st Street bridge will be closed until the temporary supports are removed and the bridge is declared sound.

Officials found two bodies in the cab of one of the trucks. Its driver often traveled with a partner.

That truck was owned by the Willis Shaw trucking company of Arkansas.

The other truck -- which investigators now think was attempting to pass a slow-moving vehicle when it slammed into the truck from Arkansas -- was owned by the Gorten trucking company in Auburn. Its load of paper bales was continuing to burn Monday afternoon.