There was a fatal explosion in western Iowa this morning at a railroad yard in Council Bluffs. John Bromley, a spokesman for the Union Pacific Railroad, says three men suffered injuries that apparently were not serious and one was killed as they worked in a railcar maintenance yard about 9:30 this morning. Union Pacific has its national headquarters in Omaha, and the men were working in a maintenance shop at the railroad yard in Council Bluffs when the explosion occurred.Council Bluffs Fire Marshal Jeff Hutcheson says his office was called soon after the incident at a railroad maintenance shop on the city’s north side. Initial reports from the firest fire companies on-scene were that there was no fire, and one fatality. They say it looks like the man who died was working on a brand-new fuel tank, getting it ready to install in a railcar that was there being serviced in the workshop. He may have been operating a portable grinder when its sparks ignited some unknown vapor, fron an un-identified source. The cause of death will be known once they do an autopsy Wednesday. Three people also injured in the explosion were identified as Union Pacific employees, and emergency workers say their injuries did not appear to be life-threatening. They were taken to local hospitals but officials can’t confirm whether they were admitted or treated and released, or tell us where the men were from. The tank involved in the explosion was to be used as a fuel container, but the fire marshall says it had never been filled. All indications are it was a brand-new tank, from a manufacturer, and he says the workmen were preparing it to be installed in a railcar. The dead man’s been identified as 46-year-old Daniel J. Weinert of Omaha. About 22 people work at the Union Pacific Heritage Park site, which is part of a former Chicago and Northwestern railroad roundhouse that’s used today to maintain vintage passenger cars.