PHOTOS: Firefighters responded to a Union Pacific engine explosion in Summit County in the early hours of Saturday. Firefighters were dispatched with Uinta County Fire and Summit County Ambulance to an incident involving a Union Pacific engine that had an explosion at approximately 3 a.m., said a Facebook post from North Summit Fire Service District. No one was injured in the blast, the post said. No other train cars were damaged, officials added. The cause of the explosion is under investigation. Gephardt Daily will have more on this developing story as information is made available.