(Preble County, OH)--Eastbound I-70 was shut down in Preble County for a few hours Tuesday night and into Wednesday morning after a semi caught fire. On Wednesday, engineers will look for structural damage on a highway’s overpass. The semi caught fire very near the Preble County Line overpass. 25,000 pounds of cardboard ignited when the semi’s brakes caught fire. Firefighters feared the heat may have damaged the overpass. "Structural failure would be our primary concern. I think there's been a handful of national examples of significant damage to overpasses," said one firefighter. The initial indication was there was no damage. Both 70 and Preble County Line Road were open by 3 o'clock on Wednesday morning.