WASHINGTON – The twice-daily Empire Builder passenger trains through Winona were cancelled because they otherwise might be stranded en route by an impending strike against major freight railroads. The Empire Builder has daily departures from Chicago, Portland and Seattle. The train travels on tracks owned by freight railroads whose unions have threatened a strike at the end of the week. Also cancelled were other Amtrak schedules between Chicago and Los Angeles, San Antonio and San Francisco. These trains normally operate on four-day and five-day round trips.